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bennerman
08-28-2010, 14:44
Hi, I am currently doing section one of the diving course questions, and I have a few questions that either weren't covered, or I somehow managed to miss... firstly, I know mask squeeze is prevented by exhaling through the nose, but the question also asks how often it has to be done, which I didn't notice in the book... I am fairly sure it is either every metre, or whenever you feel discomfort (I know "whenever you feel discomfort" is a bad answer for ear equalising, so I am not sure). Any ideas?

Tom H
08-28-2010, 16:55
Yeah, I would say when you feel discomfort. I rarely get mask squeeze, but I think once in a while I'm not automatically exhaling through the nose and I feel the pressure. Not sure why it's so infrequent--maybe others have some insight.

tonka97
08-28-2010, 17:07
I would suggest ensuring that your mask is not too tight.

I have never had a mask squeeze, but do find myself exhaling automatically occasionally into the mask.

It is not typically a big deal at all, and I don't think about how often I breathe into the mask.

I would be more concerned with protecting my ear drums!

bennerman
08-28-2010, 17:24
I know, but th question specfically asks for me to say how often to do it

scubadiver888
08-28-2010, 17:44
Hi, I am currently doing section one of the diving course questions, and I have a few questions that either weren't covered, or I somehow managed to miss... firstly, I know mask squeeze is prevented by exhaling through the nose, but the question also asks how often it has to be done, which I didn't notice in the book... I am fairly sure it is either every metre, or whenever you feel discomfort (I know "whenever you feel discomfort" is a bad answer for ear equalising, so I am not sure). Any ideas?

If you are studying PADI they don't have a specific recommendation for equalizing the air space in your mask. In general, you equalize ANY air space (mask, ears, sinus) during descent as needed. For sinus and ears, you should equalize often and before you feel any pain. If you feel too much discomfort, ascend a few feet and equalize before going any deeper. For mask squeeze, it is less critical and there for you can equalize as you feel discomfort.

Something else to understand is that the change in pressure is greatest at the surface. At 33 feet the pressure would be 2 times. At 66 feet you are twice as deep but the pressure is only 3 times.

This means that when you first start desending you need to equalize much more frequently than when you are at depth. For example, if I go from 5 feet to 10 feet I might need to equalize 3 times but if I go from 60 feet to 65 feet I might not need to equalize at all.

Finally, I have seen NUMEROUS people who suffered ear damage due to insufficient equalization. Their ears will never be quite the same. I have only seen one person suffer from mask squeeze. He looked like a dork for a couple of days but fully recovered.

bennerman
08-28-2010, 17:49
thanks :)

bennerman
08-28-2010, 18:50
I have only TWO lines to describe how to figure out proper weighting... the information is this long:

1. Enter the water with al - Anonymous - Fvb9kA63 - Pastebin.com (http://pastebin.com/Fvb9kA63)

And I write rather large... any ideas?

bennerman
08-28-2010, 19:16
Are these correct?

How a wetsuit works: The suit traps a layer of water between the suit and the diver. This water is then heated by the body's natural heat to a level that is more comfortable for the diver.

How a drysuit works: The suit is made water tight and filled with air, keeping the diver dry. A special undergarment is warn that is designed to keep the diver warm.

scubadiver888
08-28-2010, 19:24
I believe the question you are trying to answer is: Explain how to check for proper weighting.

Your instructor can accept an answer that assumes you are not a total idiot. The answer doesn't have to be proper english either. Things like keeping your regulator in your mouth and being prepared to kick or re-inflate your BCD have less to do with checking for proper weighting and more to do with not drowning.

What are the key things to look for when checking your weight? Full breath, empty BCD, should float at eye level. If sink, reduce weight. Otherwise, exhale and descend. If you cannot descend, add weight.

Realistically, there just have to be enough in the answer that it looks like you know what you are talking about. If details are missing it is okay. The instructor will go over the answers with everyone and confirm you have the details as well. In other words, it is a combination of what you write in the work sheet and what you say in class that gives you a pass for this portion of the work.

Additionally, if you don't quite have this answer down pat, it gives some future instructor the opportunity to sell you Peak Performance Buoyancy training. Your instructor would be more concerned if you couldn't answer the question "What is the most important rule in scuba diving?" Or you implied (or openly said) NDLs are merely suggestions.

The key thing to remember about scuba diving is that the instructor will do what it takes to make sure you pass. In school, you get training, you are tested and there is a chance you'll fail. In scuba, you get the training, you do the workbook questions, you discuss anything you got wrong, you get more training, you do practical work in the pool, you go over anything you got wrong, you get evaluated in open water. Unless you are an obvious danger to yourself or your potential buddy... you pass.

bennerman
08-28-2010, 19:44
much obliged :)

tonka97
08-28-2010, 20:03
Nice thread

TommyB
08-28-2010, 20:17
Are these correct?

How a wetsuit works: The suit traps a layer of water between the suit and the diver. This water is then heated by the body's natural heat to a level that is more comfortable for the diver.

How a drysuit works: The suit is made water tight and filled with air, keeping the diver dry. A special undergarment is warn that is designed to keep the diver warm.

Yes
Yes and no.. can be filled with air / argon / etc. For cold temps most use argon.

quick course

Dry suit - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Dry_suit)

Wetsuit - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Wetsuit)

bennerman
08-28-2010, 20:34
I have that written down as "filled with a gas" on the actual worksheet

bennerman
08-29-2010, 11:10
This doesn't mention what to do against a current encountered on the bottom, only what to do when you encounter one on the surface... any ideas?

ScottW
08-29-2010, 11:44
This doesn't mention what to do against a current encountered on the bottom, only what to do when you encounter one on the surface... any ideas?
Continue reading the manual and watching the video. The answer is in there, I promise. :smiley20:

bennerman
08-29-2010, 11:45
if you say so :P

bennerman
08-29-2010, 14:42
Ok, so for table one of dive tables, you get the pressure group by taking the depth (or next highest interval of depth), looking at the time below (or next highest interval), and the letter across is the pressure group? And for table two, you take the the group you were in when you got out of the water, move to the right to find the time you have spent out, and then the letter below is your new pressure group. Is that correct?

navyhmc
08-29-2010, 16:12
You pretty much have he gist of it. The hardest part of the tables is the repetative dive. Here's a way o think about it:

When you start your first dives, your body is 100% saturated with Nitrogen (N) and oxygen for that matter-but that's immaterial for the tables-at the water surface. Even though you have N is your system , call it your baseline of zero for excess N.

When you dive, you add pressure which adds N to your system at a steady rate faster or slower depending on the body tissue but again this is background for advanced stuff later. The longer you stay down the more N you absorb into body tissues. You're not doing deco dives so there is a point that at a given depth, you have enough N in your tissues that anymore will cause microbubbles in tissue if you stay any longer. This is the No Decompression limit for that depth (NDL).

Being a good diver, you have planned your dive and you head to the surface before your NDL. Your N loading for that depth at the end of your dive is represented by a letter. The higher the letter (M vs. L vs. C) the more N that's in your system. This is the right side of table 1. Remember this letter

When you get to the surface and start you surface interval, you are off-gassing that excess N. It leaves the body at a steady rate. In theory, it takes 12 hours to fully off gas. Some say 24, but for purposes of the tables, it's 12 hours. You get credit for the off-gassed N you lost while resting on the surface. But if you dive again in less than 12 hours, you still have N in your system from the previous dive. This is table 2. Start with your End of dive pressure group letter and follow is horisontally to the right until you find the time span that meets the length of your SI. This is your pressure group at the end of the surface interval - remember this letter.

That amount of additional Nitrogen still in your system is effected differently depending on the depth of your next dive. So you have to know the depth for the second dive. Go to the back side and find the planned depth on the left side (let's say 50' )follow it horizontally until your in line with the vertical column that has your end of SI press group at the top ( "C"). On the PADI Tables, the TOP white box is residual nitrogen time - this is the amount of nitrogen still in your system from the first dive, the easiest way to show this is as the amount of nitrogen that would be in your body if it was the first dive for that amount of time. So starting your second dive, you have the same amount of N is your sytems as you did if your first dive had been to 50' for 17 minutes.

Here's were it gets tricky: if you're 17 minutes into your first dive at 50' and your NDL is 80 minutes, you can only stay MORE 63 minutes. Since this is the second dive, you've got "C" nitrogen left in your system and it's equivient to 17 minutes of diving at 50' your Adjusted NDL for the second dive is 63 minutes. So your second dive was 23 minutes (for simplicity sake) you still had that 17 minutes if N from dive one in your sytem that didn't go away during the dive so you have to account for those 17 minutes along with you actual bottom time of 23 minutes. At the end of the second dive, the amount of nitrogen in your system is the same at 23 minutes as it would have been if this was your first dive of 40 minutes (17 min RNT and 23 minutes Actual Bottom Time or ABT- 17+23=40) remember that 40 minutes....

At the end of dive 2, your back to table one. 50' for 40 minutes (ABT plus RNT) Since table 1 is your dive, the end of dive reptative group is "M". And you start back over. Note since you've accounted for the extra nitrogen your took with you on dive 2 from dive 1 after your SI, it's now part of dive two's Nitrogen load so you can forget about dive on and calcualte your SI and all from the 40 minutes of nitrogen from dive 2. even though it was only 23 minutes.

Also get the table tutor from Scuba Toys: Table Tutor reviews and discounts, ScubaToys (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=TableTutor) download it, install it and send joe and larry a pm with the shareware number and they'll send you the unlock code for free-save $15 us!

bennerman
08-29-2010, 16:50
AHA!
Ok, the sample question is:
First Dive: 50ft at 40 minutes, surface interval of 1 hour, and second dive of 40 ft at 60 minutes. What is my pressure group?

So, tell me if I get this right:
The first dive was 50ft, and then you go down to 41 minutes (being the closest number rounded up). This gives a pressure group of M. M after 1 hour turns into D. a D diving at 40 feet would have a RNT of 25 minutes. The RNT plus the ABT would be 85 minutes (25 + 60). A person in group D being under for 85 minutes at 40 minutes would be a member of group S, so the answer is S.

navyhmc
08-29-2010, 17:09
That's it. Now, give youself a 1:45 SI, your next dive is back to 50' for 30 minutes. What's your end of dive group?

bennerman
08-29-2010, 17:30
First Dive: 50ft at 40 minutes, surface interval of 1 hour, second dive of 40 ft at 60 minutes, surface interval of 1:45, and a 3rd dive at 50 feet for 30 minutes?

bennerman
08-29-2010, 17:35
Trick question, I would be too exhausted before my 3rd dive...
...
...
...
Ok, I think the answer is T

navyhmc
08-29-2010, 17:55
Your 2nd dive end group is "S" 1:30 later your "C". (a C diver is 1:28 - 1:49) RNT for a C diver is 17 minutes at 50'. Your 30 min dive to 50' would have a total bottom time of 47 minutes. (RNT of 17 pluse ABT of 30 = 47 minutes) at 50' is an "O" diver.

The trick question would be a 3rd dive to 90' for 20 minutes...7 minutes RNT with Adjusted NDL of 18 minutes so 20 minutes planned would put you into deco - deco is bad, mmmmkay? Never mind that deeper dives should be done first.

bennerman
08-29-2010, 17:59
I accidentally looked at the area containing 45 minutes, instead of an hour and 45 minutes, so I got "I" instead of "C" after SI

navyhmc
08-29-2010, 18:42
It's not hard after the light bulb clicks. Get the tutor and practice to your hearts content.

bennerman
08-30-2010, 22:55
The manual doesn't mention anything about the minimum SI between specific dives or how to find it, atleast not the section to which this sheet pertains. Also, there is no "figure 1 on page 250" regarding the compass, so what would the part that shows reciprocal course be called?

navyhmc
08-30-2010, 23:13
Usually the rule is that a SI less than 10 minutes is considered part of the same dive for tables so 10 minutes is usually considered the minimum SI. As far a reciprocal course, it's 180 degrees off your current course. Have no idea about fig 1.

bennerman
08-30-2010, 23:20
I knew about how to find the reciprocal course, just not the figure in question. I shot up an email to the dive shop. Thanks

gNats
08-30-2010, 23:46
Navy. You should be an instructor.

bennerman
08-31-2010, 00:06
What she said :3

emclean
08-31-2010, 08:05
Navy. You should be an instructor.
he is, just on teh web, and not in the LDS. a fact that i an glad of, i would hate to see him too buisy to post here.

scubadiver888
08-31-2010, 22:14
The manual doesn't mention anything about the minimum SI between specific dives or how to find it, atleast not the section to which this sheet pertains. Also, there is no "figure 1 on page 250" regarding the compass, so what would the part that shows reciprocal course be called?

You might want to post the question you are trying to answer. If navy could have seen the question he would have realized it was about calculating the minimum surface interval between two specific dives. Navy was assuming you were looking for the smallest surface interval, period.

The PADI dive tables come with a manual entitled Recreational Dive Planner. Page 24 of this manual explains how to calculate the minimum surface interval.

Let's say you are going to do two dives. The first dive will be to 65 feet for 32 minutes. The second dive will be to 30 feet for 140 minutes. The minimum surface interval is the shortest period of time you must wait until you start the second dive.






Look at it as filling in the information you have. To plot a double dive you start at pressure group A and you need to fill in:

depth 1
bottom time 1
PG 1
surface interval
PG 2
depth 2
bottom time 2
PG 3
First step is to calculate your pressure group after the first dive. Look up 65 feet and you see there is only 60 and 70 feet. So I round up to 70 feet. Go down the 70 column until you find 32 minutes or higher. Turns out there is an entry for 33 minutes. Go sideways and you should find pressure group P.

Up until now you would plug in the information from the top down (or left to right on the dive profile charts in your log book). Now you need to work it from both side to arrive in the middle. Depth 1 gets rounded up to 70 feet, bottom time 1 gets rounded up to 33 minutes. 70 feet at 33 minutes is pressure group P. Now we cannot go any further down the list. So we switch to working from the bottom up.

What does 'bottom up' mean? If from the top down means use table 1 then bottom up means use the table 3 on the back of your card. on table 3, find the depth 2. There is no 30 row so we round up to 35 feet. Go across until you find a blue number that is equal to or greater than 140 minutes. You should find 143 minutes. Go up from there and you should be in pressure group L.






So now we have:

depth 1: 65 feet
bottom time 1: 32 minutes
PG 1: P (calculated from depth and bottom time)
surface interval: ???
PG 2: L
depth 2: 30 feet
bottom time 2: 140 minutes
PG 3: Z (minimum SI will always result in pressure group Z)
So how long do you have to wait for pressure group P (row) to reduce to pressure group L (column). Look on table 2. Go to row P, go across until you get to column L. The range is 0:17 to 0:21. So the minimum is 17 minutes.
Oh, and the attached pictures are figure 1 from page 250 and the A, B, C images for the answer.
76577658

navyhmc
08-31-2010, 23:40
Thanks 888. You're right, I didn't think about the bottom up calc.

bennerman
09-08-2010, 17:26
am I expected to remember everything in the summary of the first dive from the manual for tomorrow, or will the instructor walk me through everything?

navyhmc
09-08-2010, 17:34
If the instructor is worth his pay, he'll give you a step by step. Remember, they are usually setting you up for success.

ScottW
09-08-2010, 18:50
am I expected to remember everything in the summary of the first dive from the manual for tomorrow, or will the instructor walk me through everything?
The summary just lets you know what you'll be accomplishing. It's not necessary to memorize it.
They should tell you the skill(s) or exercise(s) being done, then explain how it should be done, then show you how it's done underwater and maybe above depending on the skill or excercise, then let you try it and then let you practice it. Hopefully when they explain how it's done they give you a why, if not ask them 'why do we need to know this?'

Lenaxia
09-08-2010, 19:35
am I expected to remember everything in the summary of the first dive from the manual for tomorrow, or will the instructor walk me through everything?

Sadly my instructor never really drilled this into us, it was pretty much glossed over so as it stands right now, I can't use tables. I plan on rectifying this in the near future but been too concentrated on other stuff to really sit down and make heads or tails of it.

If your instructor glosses over it, ask him after class to go into more detail about it. Ask for some examples or have him throw together some random dive profiles so you can practice and he can check.

PACKRMAN
09-08-2010, 19:56
Bennerman,

Hey buddy, don't over think this. Let your instructor instruct. Relax......Oooosaaaaa....

Really, you've been thinking about this for a year and a half. Don't get worked up. You're doing this to have fun so have fun. Blow some bubbles and get wet. Your instructor will take care of you. You have years to get good at it, don't try to be a Pro on the first dive.

calm


easy


slow



breath


:smiley20:

scubadiver888
09-08-2010, 20:21
am I expected to remember everything in the summary of the first dive from the manual for tomorrow, or will the instructor walk me through everything?

Your instructor wants you to succeed. I would like to say, when I first got my driver license I pass the test and was 'okay' to drive. After years of driving I have gotten a lot better at it. The same thing holds for diving. You have all the knowledge you need to start diving. You might not remember it all, all the time but over time you will. With practice you will get better. Right now you just have to show that you know most of it and you will master it all with more practice.

scubadiver888
09-08-2010, 20:47
Sadly my instructor never really drilled this into us, it was pretty much glossed over so as it stands right now, I can't use tables. I plan on rectifying this in the near future but been too concentrated on other stuff to really sit down and make heads or tails of it.

If your instructor glosses over it, ask him after class to go into more detail about it. Ask for some examples or have him throw together some random dive profiles so you can practice and he can check.

I would suggest focusing on anything which would be hard to demo over the internet. Worst case, there are a few good people here who could give you some help on things like dive tables.

By the way, Lenaxia, when you are ready to learn dive tables I'm sure navy and I can help you out. :)

The most important thing to remember is the basic concept. You fill up with nitrogen. The deeper you go the faster you fill up. When you wait on the surface, you empty. If you are on the surface for 6 hours, you will be totally empty (pressure group A). If you still have nitrogen in you and you do a second dive, you won't be empty and therefore you'll fill up quicker.

Lenaxia
09-08-2010, 21:29
I would suggest focusing on anything which would be hard to demo over the internet. Worst case, there are a few good people here who could give you some help on things like dive tables.

By the way, Lenaxia, when you are ready to learn dive tables I'm sure navy and I can help you out. :)

The most important thing to remember is the basic concept. You fill up with nitrogen. The deeper you go the faster you fill up. When you wait on the surface, you empty. If you are on the surface for 6 hours, you will be totally empty (pressure group A). If you still have nitrogen in you and you do a second dive, you won't be empty and therefore you'll fill up quicker.

Haha yeah, all that makes sense to me, plus my PDC does all those calcs for me. I just glance at my N2 loading chart on the screen and guesstimate if I have enough for another dive, I always stay conservative too, last thing I want is to push my NDL and end up with a deco ob on a single tank dive. I'll sit down one of these days and actually figure out how to read all the groups and everything on that damned padi chart.

TwistedSister209
09-08-2010, 21:31
Bennerman--
If you are using PADI, the plastic Recreational Dive Planner, can walk you through almost any problem. Relax, breathe, and read. You can follow arrows.
Lots of great advice here. WE all want you to succeed.

mitsuguy
09-08-2010, 23:37
If you are on the surface for 6 hours, you will be totally empty (pressure group A).

Technically, this is incorrect... there really is no pressure group once you have been cleared of nitrogen... If you only went back to A, then you assume there is still nitrogen in your body...

For example, if it is your first dive of the day, your NDL for 60' is 55 minutes, per PADI RDP, however, if you are an A diver, then your adjusted NDL is 49 minutes... you can clearly see the difference here... Once you have spent 6 hours out of the water, you are instructed to plan the next dive as if it was the first dive... It doesn't have to be 6 hours though, it depends on what the previous dive(s) were - for example, a diver in pressure group C need only wait 4 hours and 11 minutes to consider the next dive as a first dive...

Quero
09-09-2010, 02:33
The most important thing to remember is the basic concept. You fill up with nitrogen. The deeper you go the faster you fill up. When you wait on the surface, you empty. If you are on the surface for 6 hours, you will be totally empty (pressure group A). If you still have nitrogen in you and you do a second dive, you won't be empty and therefore you'll fill up quicker.

As mental imagery, this may be helpful, but it's somewhat oversimplified.

First, even after a six hour SI, it's not safe to assume you're "empty" of N2, but instead that the fast (theoretical tissue) compartments have off-gassed. If you were really "empty" it would be okay to fly after six hours, and we all know that it's not. There are still bubbles in the tissues after six hours, but since the bubbles are present mainly in the "slow" compartments, they take longer to saturate as well as desaturate, and we can for practical purposes go ahead and plan the subsequent dive as if it were not part of the previous series.

In other words "fill up" and "empty" out happens at different rates for different (theoretical tissue) compartments and is nothing like the mental imagery of just filling up a container and emptying it. If I may, I'd like to offer a couple of different mental images-- for filling up, imagine a spilled amount of liquid on a tabletop; what sort of material will absorb the excess quicker, cardboard, newspaper, or paper towel? Once saturated, which of the three will dry out quickest afterwards? Different tissue compartments (representing theoretical rates of saturation in our bodies) absorb and hold on to N2 in a similar way. For off-gassing, I like to think that it's a bit more like a bunch of clothes drying after being laundered. You hang everything up, and after half an hour the faster drying stuff like a thin cotton shirt will be dry while heavy stuff like blue jeans will still be damp, really heavy stuff like towels will only begin to show some drying, and if you've washed a stuffed toy, that may still be dripping wet! The theoretical models of N2 saturation are based on many, many compartments representing different theoretical tissue types and the rates at which they are assumed to absorb and release gas.

@lenaxia: the table is just a different manifestation of the information the dive computer provides. What you really should be confident that you understand are the general concepts behind both of them. It's not really necessary (IMO) to have drilled the flat table into one's brain. Learn all about the functions your computer provides and use these features fully to plan and monitor your dives.

scubadiver888
09-09-2010, 23:36
I didn't mean to imply that after 6 hours it is okay to fly. As you pointed out "we all know that it's not [okay to fly]."

Your analogy of cardboard, newspaper, paper towel makes sense to me but I'm not sure if it adds value to your average open water diver.

scubadiver888
09-09-2010, 23:44
Haha yeah, all that makes sense to me, plus my PDC does all those calcs for me. I just glance at my N2 loading chart on the screen and guesstimate if I have enough for another dive, I always stay conservative too, last thing I want is to push my NDL and end up with a deco ob on a single tank dive. I'll sit down one of these days and actually figure out how to read all the groups and everything on that damned padi chart.

Thre is one thing that is implied by my message but not explicitly stated. I noted that as you go deeper, you fill up with nitrogen faster. If your at 90 feet and your computer says you have 3 minutes until NDL is reached it is assuming you will stay at 90 feet. If you ascend to 60 feet, the nitrogen loading will slow down. This means your NDL might change to 20 minutes (just a guess). Additionally, if I'm your buddy and I stay 10 feet above you all the time, you'll hit your NDL before me (assuming our computers are using the same algorithm).

bennerman
10-18-2010, 18:51
For filling out my log book:
it has a space called "surface" and a place called "bottom". I assume "surface" means SI, and "bottom" means total bottom time? If so, since it was one dive, "surface" should be blank or N/A, right? and if the dive lasted from 11:30 to 12:00, "bottom" should read "00:30", right?

Quero
10-19-2010, 04:49
Hey b-man--

The field in your log book called "surface" is indeed for noting the surface interval, and yes, you only fill it in between two dives, not before the first dive. It's used to figure out your nitrogen offgassing in order to calculate new maximum bottom times for a subsequent dive.

The part called "bottom" is the time from submerging until you begin your ascent. It does not count the safety stop (or deco stop) time. So if you had a 30 minute total dive time and did a standard 3 minute safety stop, your bottom time would be the time you spent diving from your descent until the time you began your ascent + 3 minutes for the stop + 1 minute ascent time from the stop to the surface + whatever time it takes you to get from your depth when you began your ascent to the safety stop depth.

However, most recreational divers simply count the total dive time in their logs and don't bother with the fractional times (just as you did in your question), or they count everything except the safety stop as "bottom time" so that by adding the bottom time and the stop the total dive time results.

Tech divers need to be very careful with times, however, so if you aspire to tech diving, you might want to get into the habit of planning those times and following your plan as you dive.

bennerman
10-19-2010, 16:06
Hey b-man--

The field in your log book called "surface" is indeed for noting the surface interval, and yes, you only fill it in between two dives, not before the first dive. It's used to figure out your nitrogen offgassing in order to calculate new maximum bottom times for a subsequent dive.

The part called "bottom" is the time from submerging until you begin your ascent. It does not count the safety stop (or deco stop) time. So if you had a 30 minute total dive time and did a standard 3 minute safety stop, your bottom time would be the time you spent diving from your descent until the time you began your ascent + 3 minutes for the stop + 1 minute ascent time from the stop to the surface + whatever time it takes you to get from your depth when you began your ascent to the safety stop depth.

However, most recreational divers simply count the total dive time in their logs and don't bother with the fractional times (just as you did in your question), or they count everything except the safety stop as "bottom time" so that by adding the bottom time and the stop the total dive time results.

Tech divers need to be very careful with times, however, so if you aspire to tech diving, you might want to get into the habit of planning those times and following your plan as you dive.

was a 20ish foot dive, so safety stop didn't really come into question. for intents and purposes, I just put 30 minutes in "bottom", then?

scubadiver888
10-19-2010, 18:57
was a 20ish foot dive, so safety stop didn't really come into question. for intents and purposes, I just put 30 minutes in "bottom", then?

As Quero said, the bottom time is really the moment you descend to the moment you START to ascend. The time it takes you to get to the surface (including any safety stops) should not technically be included. However, at 20 feet and ascending at an appropriate rate of 30 feet per minute should take you 40 seconds. You could put 29 minutes for bottom time if you want to be pedantic.

The reality is, if you aspire to be a technical diver or keep incredibly accurate logs then you need to note the time you start the descend, the time you start the ascent and any safety stops you do. If you don't know exactly when you started the ascent then maybe you ascended at 60 feet per minute and it took you 20 seconds. Maybe you ascended at 5 feet per minute and it took you 4 minutes (highly unlikely but possible).

So was the bottom time 30 minutes minus 40 seconds? Minus 20 seconds? Minus 4 minutes? From my experience, you probably took between 20 and 60 seconds to ascend from 20 feet. You could easily claim 30 minutes or 29 minutes and no one would question it.

If you want to be a PADI Professional, the number of "dives" you do matters. You need a certain minimum to enroll in certifications and another minimum to graduate. A dive is 20 feet for 20 minutes, essentially; there is more to the definition but for this conversation you did a 'dive'. You can log it as 20 feet for 29 minutes or 20 feet for 30 minutes and it will make no difference.

Bottom line, don't sweat the small stuff. Don't be too concerned with whether this was a 29 minute or 30 minute dive.

There will be other dives which will be even harder to judge. I did a dive which was down a wall to 80 feet (took me around a minute to get down) then I swam along the bottom towards shore for an hour. By the time I surfaced I was at 15 feet. Was that a 1 minute dive with a REALLY slow ascent? or was that a 60 minute dive with an ascent from 15 feet? The way I looked at it (as someone working towards PADI Professional), I was below 20 feet for more than 20 minutes so it was a 'dive'.

Gonnagettanked
10-20-2010, 08:27
As Quero said, the bottom time is really the moment you descend to the moment you START to ascend. The time it takes you to get to the surface (including any safety stops) should not technically be included. However, at 20 feet and ascending at an appropriate rate of 30 feet per minute should take you 40 seconds. You could put 29 minutes for bottom time if you want to be pedantic.

The reality is, if you aspire to be a technical diver or keep incredibly accurate logs then you need to note the time you start the descend, the time you start the ascent and any safety stops you do. If you don't know exactly when you started the ascent then maybe you ascended at 60 feet per minute and it took you 20 seconds. Maybe you ascended at 5 feet per minute and it took you 4 minutes (highly unlikely but possible).

So was the bottom time 30 minutes minus 40 seconds? Minus 20 seconds? Minus 4 minutes? From my experience, you probably took between 20 and 60 seconds to ascend from 20 feet. You could easily claim 30 minutes or 29 minutes and no one would question it.

If you want to be a PADI Professional, the number of "dives" you do matters. You need a certain minimum to enroll in certifications and another minimum to graduate. A dive is 20 feet for 20 minutes, essentially; there is more to the definition but for this conversation you did a 'dive'. You can log it as 20 feet for 29 minutes or 20 feet for 30 minutes and it will make no difference.

Bottom line, don't sweat the small stuff. Don't be too concerned with whether this was a 29 minute or 30 minute dive.

There will be other dives which will be even harder to judge. I did a dive which was down a wall to 80 feet (took me around a minute to get down) then I swam along the bottom towards shore for an hour. By the time I surfaced I was at 15 feet. Was that a 1 minute dive with a REALLY slow ascent? or was that a 60 minute dive with an ascent from 15 feet? The way I looked at it (as someone working towards PADI Professional), I was below 20 feet for more than 20 minutes so it was a 'dive'.

really like your reply

Quero
10-21-2010, 04:27
was a 20ish foot dive, so safety stop didn't really come into question. for intents and purposes, I just put 30 minutes in "bottom", then?

You certainly can simply count it as a 30-minute dive in the log. No problem. Just fill in 30 in the field marked Bottom and leave the part called Safety Stop blank since you didn't actually do a separate stop.

As I said, fractional times are really only important once you begin to do extremely detailed dive planning and logging.

bennerman
11-24-2010, 19:31
This isn't related to the open water cert, but is there any way to wear doubles with a jacket type BC? I don't like the way the air seems to bubble in back inflate types.

mitsuguy
11-24-2010, 19:42
This isn't related to the open water cert, but is there any way to wear doubles with a jacket type BC? I don't like the way the air seems to bubble in back inflate types.

yes, but it doesn't work that well... I know for sure that most Cressi BCD's have holes in the plastic plate for doubles...

I might add that it may be your particular BCD, as my Hollis donut wing and plate don't "bubble" at all...

bennerman
11-24-2010, 20:03
yes, but it doesn't work that well... I know for sure that most Cressi BCD's have holes in the plastic plate for doubles...

I might add that it may be your particular BCD, as my Hollis donut wing and plate don't "bubble" at all...

All I know is I went entirely vertical when I inverted even slightly, so I dunno

mitsuguy
11-24-2010, 20:06
how much air is in it when you do this?

chances are a little more practice is all you need...

bennerman
11-24-2010, 20:12
how much air is in it when you do this?

chances are a little more practice is all you need...

there actually wasn't a lot. I was still sinking and there wasn't any weight on me (doubles are heavy, my shoulders are still sore XD)

mitsuguy
11-24-2010, 20:20
if there was little to no air in the bladder, then you aren't having a problem with the air placement in the BC, instead, it sounds like you are having a problem with weight distribution...

try moving weights to trim pockets, upper cam bands, etc...

bennerman
11-24-2010, 20:29
I also don't like the positioning of the webbing/straps, I prefer the way the jacket type is done

mitsuguy
11-24-2010, 20:32
it sounds like you are trying to defend the jacket style BC, which is fine... it works great for a lot of people... to generalize and say you don't like the positioning of the webbing / straps is a little closed minded... there are many different types of back inflate BC's, and if you include all the different ways you can set up a plate/wing with webbing/straps, then I am sure there is one that is positioned to your liking...

what type of BCD have you been trying?

FFDiver
11-24-2010, 20:35
With doubles I know i dont use any weights and will sink. I really dont know if doubles will work good with a jacket as they are not really made for it. Hopefully someone on here will have practical experience and has some better options. I have not had any issues with my shoulders and I have 104s and they are not light.

bennerman
11-24-2010, 20:42
it sounds like you are trying to defend the jacket style BC, which is fine... it works great for a lot of people... to generalize and say you don't like the positioning of the webbing / straps is a little closed minded... there are many different types of back inflate BC's, and if you include all the different ways you can set up a plate/wing with webbing/straps, then I am sure there is one that is positioned to your liking...

what type of BCD have you been trying?

I am not sure of the specific models of each one, anyways, I just like the velcro on the jacket one I used, and on the back inflate, it wasn't tight enough on me (so yeah, that could easily be the actual one, but with the velcro, I also find the jacket easier to adjust anyway)

bennerman
11-24-2010, 20:44
With doubles I know i dont use any weights and will sink. I really dont know if doubles will work good with a jacket as they are not really made for it. Hopefully someone on here will have practical experience and has some better options. I have not had any issues with my shoulders and I have 104s and they are not light.

That would be because you are probably a lot stronger than I am. as well, I am heavy, and putting extra weight on a weak, heavy structure is a lot worse than putting it on a strong, light (I assume... compared to me, anyway) structure.

mitsuguy
11-25-2010, 05:56
I am not sure of the specific models of each one, anyways, I just like the velcro on the jacket one I used, and on the back inflate, it wasn't tight enough on me (so yeah, that could easily be the actual one, but with the velcro, I also find the jacket easier to adjust anyway)

So, you are comparing a single jacket BC to a single (ill-fitting) back inflate BC. Just an example, but between various Cressi BC's, many of them use the same plastic backpack underneath the "wing" or the "jacket" and typically have the same cummerbund as well.

Now, if you are talking backplate and wing, and you are looking for something more comfortable, why not check out the Transpac or Hollis HTS2 - these guys have padded everything and include cummerbunds if thats your thing (I hate them personally)...

FoxHound
11-25-2010, 08:55
So take all that weight and hang it from fabric, or plastic, it will break especially if you are diving high capacity steel tanks.....they arent designed for use with doubles. Also, while diving doubles you need to be able to reach your valves. BCs with velcro and elastic are going to move around on your back. I dont think there is a tech instructor out there that would let you use a jacket BC, just waaaaaay too many failure points for that type of diving.

When you put a BP/W on you should only be able to fix about 2 fingers between you and the strap. This will insure proper fit and keep the tanks from moving around on your back. If it was loose like you said, thats no good, just creates problems.

If its fitted properly im sure you would be more then comfortable. Also doubles are a whole new beast to master, boyancy and trim are much different then single tank diving let alone single tank diving with a jacket type BC.

FFDiver
11-25-2010, 13:01
So, you are comparing a single jacket BC to a single (ill-fitting) back inflate BC. Just an example, but between various Cressi BC's, many of them use the same plastic backpack underneath the "wing" or the "jacket" and typically have the same cummerbund as well.

Now, if you are talking backplate and wing, and you are looking for something more comfortable, why not check out the Transpac or Hollis HTS2 - these guys have padded everything and include cummerbunds if thats your thing (I hate them personally)...

I have had good luck with my transpac on doubles and is comfortable. However just like everything else everyone is different.

bennerman
11-25-2010, 14:39
I am just pointing out what I observed, don't think for a second I won't be trying more BCDs before I make my final decision (both jacket and back inflate ones)

bennerman
11-25-2010, 14:49
So if I have got this correct, a BP/W is composed of a plate (OMS Backplate discounts on sale OMS (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=OMS_Backplate) for example), a harness (Dive Rite Basic Harness discounts on sale Dive Rite (http://www.scubatoys.com/store/detail.asp?product_id=DiveRiteBasicHarness) for example), and a wing (OxyCheq Standard Single Cylinder Wing discounts on sale OxyCheq (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=OXYStdWing) for example)?

bennerman
11-25-2010, 14:58
Sorry if I seem ignorant (I am getting a vibe of frustration from some posts people are making) but the truth is I am ignorant, I am posting here because I really want to learn, and I really do take everything being taught to me to heart. Thanks to everyone who is happily guiding me on the path to be a better diver :)

Vercingetorix
11-25-2010, 18:14
So if I have got this correct, a BP/W is composed of a plate (OMS Backplate discounts on sale OMS (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=OMS_Backplate) for example), a harness (Dive Rite Basic Harness discounts on sale Dive Rite (http://www.scubatoys.com/store/detail.asp?product_id=DiveRiteBasicHarness) for example), and a wing (OxyCheq Standard Single Cylinder Wing discounts on sale OxyCheq (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=OXYStdWing) for example)?

Yes, that is correct. The harness you reference is the Hog webbing harness. To set it up, go online; there are several illustrated resources for setting up a web harness.

FYI. I noted you have three consecutive posts. You can combine them all into a single post via the edit function. In fact, you can even do so after posting. You can simply copy all the posts into a single post, then delete the others.

bennerman
11-25-2010, 18:19
I figure since I have all of the gift cards, it won't look like I am padding my post count if I don't bother with that anymore. if it bothers people, I will fix it, but otherwise, it's just easier

TwistedSister209
11-25-2010, 18:45
Hey, B-man!
I appreciate you asking questions as I'm learning from those posting answers. I wish I had used many different BC instead of jumping in to buy what a 'friend' recommended. Would have saved me money and frustration.
I think we all see how much you want to learn--hard to recognize 'tone' in emails. Except for me, Ms Sunshine! :smilie39:

Yeah, I'm padding my posts......:smiley36:

bennerman
11-25-2010, 19:11
Cressi Scuba Diving B.C.īs - S 111 R (http://www.cressi-sub.it/Catalogue/Details.asp?id=84) this is the jacket BCD I was using (and if not, damn close).

scubadiver888
11-25-2010, 20:12
So if I have got this correct, a BP/W is composed of a plate (OMS Backplate discounts on sale OMS (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=OMS_Backplate) for example), a harness (Dive Rite Basic Harness discounts on sale Dive Rite (http://www.scubatoys.com/store/detail.asp?product_id=DiveRiteBasicHarness) for example), and a wing (OxyCheq Standard Single Cylinder Wing discounts on sale OxyCheq (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=OXYStdWing) for example)?

Hey bennerman,

Checkout BackPlate and Wing Package discounts on sale Dive Rite (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=BackPlate_Wing_Package). This will give you a list of the basic parts to a BP/W setup.

You can add a Single Tank Adapter (STA). Using a STA makes changing the tank a little easier plus it will be more secure. But a STA isn't always necessary.

For diving local, I'd recommend a steel backplate.

FoxHound
11-26-2010, 00:41
The short and sweet of er, thats exactally what you need for a BP/W, for singles you would also need tank straps as well. Thats the big thing with a BP/W, its all modular. You can get a complete setup or buy piece by piece.

Like you said, try out a lot BCs, find which ones you like. However if you do want to continue to dive doubles, BP/W is your best option.

mzbdiver
11-26-2010, 01:55
I see I'm not the only one with BP/W questions... Yay!!

Davetowz
11-26-2010, 02:41
I think those of us yet to try BP/W ask the same questions when what we probably should do is just get a plate, a simple hog harness and dive the things and then ask the questions. I get it that most are trying to buy the right thing the first time and save some green, got it, I am in the same boat. However, it would seem that with BP/W, simple is the answer.
I need to just try it. if I could just find a dive bud in central Ohio.........

FoxHound
11-26-2010, 08:41
Thats whats nice about a BP/W, it is modular, insted of having to buy a different BC for each type of diving you can modify your current rig for a lot less money.

Its really nice if you can get a chance to try things out. Its even better if you can get something that will last you through your entire diving career but lets be honest that just wont happen. As we dive more and more, we start to find out what we really want in gear. My fiance constantly tells me im am the most pickey person when it comes to gear. If i want a specific peice of kit, its for a good reason and i dont want to subsitute haha.

I have replaced almost 100% of my kit since i started diving. the only thing i have from my orginal kit purchase are the mares fins (which i only use in the tropics because the turtles are too big and heavy for that) and oceanic GT3 regs....oh and tanks.....can never have too many tanks haha

Even still having those 2, i dont regularly use them, got turtles for the drysuit, and i use 2 sets of apex regs now, kept the oceanics for stage regs.

As we evolve in our diving our gear has to evolve with us. I just think the BP/W set up is the most versitile setup, can be used for all types of diving from simple rec, tech, and cave.

scubadiver888
11-26-2010, 09:03
If you have a PADI shop near by that does TecRec, they should have a TecRec Discovery Dive (like the regular scuba DSD). They have to wear a set of doubles and see what it is like. If you can get neutral and trim properly, they have you do some valve drills. It is a real fun experience. You can then talk to the instructor about the gear and look at a real set up.

bennerman
11-26-2010, 09:06
If you have a PADI shop near by that does TecRec, they should have a TecRec Discovery Dive (like the regular scuba DSD). They have to wear a set of doubles and see what it is like. If you can get neutral and trim properly, they have you do some valve drills. It is a real fun experience. You can then talk to the instructor about the gear and look at a real set up.

My instructor let me try doubles in the pond when I ran out of skills to learn and the lake was too violent for my checkout dives. It was really fun, but again, I had problems with flopping down when I tried to go horizontal

plot
11-28-2010, 15:59
on casual dives i've let plenty of people try my backplate/wing and so far everyone has loved it and found it to be very comfortable. I'd recommend trying another one bennerman, and this time adjust the straps and everything properly so it fits well. I've found with a single tank I can let my harness be very lose and not bother me at all, but with doubles everything needs to be on you tight or the weight will shift and roll you around when it does.

the few people i know who don't like them simply like taking tons of random gear with them in jacket pockets... to each his own though. at the heart of it all, most people are recreational divers so whatever makes them feel the most comfortable for their style of diving is just great. getting into the technical world i don't think you'll find anyone diving a jacket though, mainly because bp/w's are just so modular you can adapt it to any type of setup with a new wing, or a different backplate, etc.

bennerman
11-28-2010, 16:34
what is the point of the different between the various parts? (I am going to go ahead and assume that a different wing has different capacity, and thus changes the BC's overall lift ability, but what are the different types of back plates and what do they do differently? o.o)

bennerman
11-28-2010, 17:07
I just realised, if I am losing weight, a BP/W will serve me better, seeing as it is easily adjustable, right?

scubadiver888
11-28-2010, 17:13
There are different backplate manufacturers. Each has differences like the bends in the plate, the size of the plate or the extra holes. For the most part, this is all personal preference. Some people just like certain subtle differences and are willing to pay a little more for them.

Aside from that, different plates have different weights. An aluminum plate is typically 2 lbs. A steel plate is typically 6 lbs. Some will be a little heavier (e.g. 3 lb aluminum or 10 lb steel) and some will be a little lighter (e.g. 5 lb steel).

If I was diving with a steel tank using 3mm wetsuit a steel plate would make me VERY negatively buoyant. So I would use an aluminum plate. On the other hand, using an AL80 with a 7mm wetsuit and a 7mm tunic I would be very positively buoyant. I could wear a lot of lead to make me neutral or I could use a thick steel plate and a little ditchable lead weight.

As for the wing, if I have two HP130s they will be -23.4 lbs buoyant, add to that a steel backplate, manifolds, etc. and it is easily -30 lbs buoyant. If I was using a 17 lb travel wing, fully inflated the rig would sink at the surface. I'd want at least a 32 lb wing. I might even need a 40 lb wing to safely float the rig at the surface.

I could use a 94 lb wing but then the wing would be only half full most the time. A bigger wing makes a bigger hole in the water. A bigger hole means more resistance. More resistance means I use more air. Essentially, you want to pick a wing which is not too big but not too small for the configuration you are diving with. For technical divers, they might have double HP130s, deco bottle, stage bottle, etc. This is when you might need a 60 lb wing.

scubadiver888
11-28-2010, 17:14
I just realised, if I am losing weight, a BP/W will serve me better, seeing as it is easily adjustable, right?

Not only is it easy to adjust but if your buoyancy characteristics change, you can adjust the rig to meet your changing needs.

bennerman
11-28-2010, 17:47
So I have a back plate (with the harness Colored OxyCheq Ultra Lite Back Plate discounts on sale OxyCheq (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=ColoredOxyCheqUltraLiteBackP late)), a HOG 38lb bladder HOG 38Lb Bladder discounts on sale HOG (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=HOG38LbWing) (HOG makes my fins so the name jumped out at me, hurray for brand loyalty), two sex bolts, and a crotch strap Dive Rite 1 and 2 Inch Crotch Strap W/Scooter Ring discounts on sale Dive Rite (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=DiveRite1inchStrap)

other than a tank band, do I need anything else beyond those?

plot
11-28-2010, 21:12
you need a full harness, not sure what the speed harness is that comes as an option with that backplate. other than that, just need tank bands for a single tank. with doubles you bolt it on by putting a bolt through the holes in the backplate, then the holes in the wing, then the holes in the doubles tank band. Use a wing nut to tighten.

you can buy different backplates for different conditions, you can get ultralight ones for traveling, stainless steel for cold water diving (weighs more, so it takes weight off your belt and spreads it over your back), aluminum for warm water diving, or you can just get a stainless steel plate and use it for all your diving. can mount doubles or singles to pretty much any backplate, however some might need a STA (single tank adapter). If you don't use a STA, you'll need tank bands of some sort (more common).

wings - this is the big one in my opinion. You can buy different sized wings depending on what you need. I have a 20lb single tank wing for diving a single tank with a wetsuit, and a 60lb doubles wing for twin steels and a drysuit. Some day I'll get around to getting like a 35lb wing for a single tank with a drysuit (need the weight to sink a drysuit and a wing to lift me if the drysuit floods).

Harness - the common harness is called a "HOG Harness" and it's a single 2" peace of webbing with d-rings and clips attached where needed. I have a fully adjustable harness with quick release gear to make mine easy to get on and off. Some have a chest strap, etc...

Really, you only need one harness ever. You might need multiple backplates, but more than likely you'll need multiple wings throughout your diving if you really get into a lot of different things. This is where it pays dividends, as not only are you saving a ton of money by only buying a new wing, but you can use your same harness so your diving configuration is always the same (where you have your lights clipped on, knife attached, etc.) so you're more comfortable with your gear and have a more consistent configuration despite what tank is on your back. The harness can also be completely customizable adding pockets/drings where needed.

Another huge plus is you aren't locked into one manufacturer. You can make your own hog harness with 2" webbing and the right hardware so you don't even go through a manufacturer here... any harness works with any bp/w. Most wings and backplates are 100% interchangeable between manufacturers too, with a few exceptions being some oddball backplates out there to accommodate some specific thing.

bennerman
11-28-2010, 21:17
you need a full harness, not sure what the speed harness is that comes as an option with that backplate. other than that, just need tank bands for a single tank. with doubles you bolt it on by putting a bolt through the holes in the backplate, then the holes in the wing, then the holes in the doubles tank band. Use a wing nut to tighten.

you can buy different backplates for different conditions, you can get ultralight ones for traveling, stainless steel for cold water diving (weighs more, so it takes weight off your belt and spreads it over your back), aluminum for warm water diving, or you can just get a stainless steel plate and use it for all your diving. can mount doubles or singles to pretty much any backplate, however some might need a STA (single tank adapter). If you don't use a STA, you'll need tank bands of some sort (more common).

wings - this is the big one in my opinion. You can buy different sized wings depending on what you need. I have a 20lb single tank wing for diving a single tank with a wetsuit, and a 60lb doubles wing for twin steels and a drysuit. Some day I'll get around to getting like a 35lb wing for a single tank with a drysuit (need the weight to sink a drysuit and a wing to lift me if the drysuit floods).

Harness - the common harness is called a "HOG Harness" and it's a single 2" peace of webbing with d-rings and clips attached where needed. I have a fully adjustable harness with quick release gear to make mine easy to get on and off. Some have a chest strap, etc...

Really, you only need one harness ever. You might need multiple backplates, but more than likely you'll need multiple wings throughout your diving if you really get into a lot of different things. This is where it pays dividends, as not only are you saving a ton of money by only buying a new wing, but you can use your same harness so your diving configuration is always the same (where you have your lights clipped on, knife attached, etc.) so you're more comfortable with your gear and have a more consistent configuration despite what tank is on your back. The harness can also be completely customizable adding pockets/drings where needed.

Another huge plus is you aren't locked into one manufacturer. You can make your own hog harness with 2" webbing and the right hardware so you don't even go through a manufacturer here... any harness works with any bp/w. Most wings and backplates are 100% interchangeable between manufacturers too, with a few exceptions being some oddball backplates out there to accommodate some specific thing.

Problem is shipping solid steel is expensive as hell to canada, so I need to go as light as possible. So aside from spending an extra 10 dollars for a respectable harness, I pretty well have everything I need there?

scubadiver888
11-28-2010, 23:09
Problem is shipping solid steel is expensive as hell to canada, so I need to go as light as possible. So aside from spending an extra 10 dollars for a respectable harness, I pretty well have everything I need there?

Bennerman,

Why don't you buy local? I priced out an inexpensive BP/W on a few online stores. The exchange rate is no longer an issue because our dollar is close to par with the American dollar. After putting together a BP/W configuration I can calculate the shipping and handling but I cannot calculate the duties. The duties are typically 20%. So I can multiple the final amount by 1.2 and get the final cost.

I looked at various configurations and went into a local store to see what they could put together. I let them know that I wasn't independently wealthy and was just trying to put together a kit as inexpensively as possible. I did not say i was considering purchasing the kit online. I just impressed upon them that I needed to be frugal and was shopping around for a good set up for an inexpensive price. I made it clear I was not going to purchase it right then. I needed time to save up the money and wanted to shop around. I did promise them I would come back before I purchased the kit from someone else.

The shop seemed to appreciated my honesty and gave me a good quote. I would recommend you do the same thing.

Go to a few shops in your area. If they don't have BP/W setups prominently displayed move on. If they are going to be able to give you a competitive price, they have to sell a fair number of the units. If they offer to order it in special, there is no way they'll be able to match the price of someone who sells 20 or 30 of these a year.

If I remember correctly, you are in the Ottawa area. If this is correct, you have a few shops who will sell BP/W.

bennerman
11-29-2010, 13:48
Bennerman,

Why don't you buy local? I priced out an inexpensive BP/W on a few online stores. The exchange rate is no longer an issue because our dollar is close to par with the American dollar. After putting together a BP/W configuration I can calculate the shipping and handling but I cannot calculate the duties. The duties are typically 20%. So I can multiple the final amount by 1.2 and get the final cost.

I looked at various configurations and went into a local store to see what they could put together. I let them know that I wasn't independently wealthy and was just trying to put together a kit as inexpensively as possible. I did not say i was considering purchasing the kit online. I just impressed upon them that I needed to be frugal and was shopping around for a good set up for an inexpensive price. I made it clear I was not going to purchase it right then. I needed time to save up the money and wanted to shop around. I did promise them I would come back before I purchased the kit from someone else.

The shop seemed to appreciated my honesty and gave me a good quote. I would recommend you do the same thing.

Go to a few shops in your area. If they don't have BP/W setups prominently displayed move on. If they are going to be able to give you a competitive price, they have to sell a fair number of the units. If they offer to order it in special, there is no way they'll be able to match the price of someone who sells 20 or 30 of these a year.

If I remember correctly, you are in the Ottawa area. If this is correct, you have a few shops who will sell BP/W.

Nope, Brantford. Closest dive shop is in Simcoe, and they are selling the place, so yeah

scubadiver888
11-29-2010, 14:15
Nope, Brantford. Closest dive shop is in Simcoe, and they are selling the place, so yeah

It isn't wildly convenient but I would suggest you go to Kitchener and check out Tri-City Scuba (http://www.scubacentre.ca/). They have Halcyon, Zeagle, Hollis, XSScuba (Highland Backplate) and Dive Rite. I haven't done business with Tri-City but they do their checkout dives at the same watering hole my shop uses. I've watched them and talked with some of them. I like them and would definitely check them out if I was in the Kitchener area.

The other option is find the gear you like, go to the manufacturer's web site and see if they have a locate dealer function. If you try the latter, be warned, some shops will claim to be a dealer just to get you in the store. Then they try to sell you something else. I avoid them.

I think Tri-City should be able to hook you up.

P.S. there might be more for you down towards Niagara Falls or Lake Erie. I know there is some pretty sweet diving down that way. I'm half way between Niagara Falls/Lake Erie and Kingston/Brockville so I tend to go Kingston/Brockville but I talk to guys who live out in Kitchener, Burlington or even Oakville and they head down to Erie all the time.

bennerman
11-29-2010, 14:23
Kitchener has bad memories for me, but since it is for a possibly good BCD, I will stomach it and go have a look as soon as I can. Thanks :)

bennerman
11-29-2010, 20:44
HOG has a wing, a bladder, and an air cell all for the same price (32lb, 38lb, and 58lb, respectively). Firstly, they all mean the big inflaty thing what goes on that thar plate, right? secondly, if I do end up getting that really light plate, I will probably only need the 32lb, right?

scubadiver888
11-29-2010, 21:14
HOG has a wing, a bladder, and an air cell all for the same price (32lb, 38lb, and 58lb, respectively). Firstly, they all mean the big inflaty thing what goes on that thar plate, right? secondly, if I do end up getting that really light plate, I will probably only need the 32lb, right?

A wing is the big inflaty thing that goes between the plate and the tank. A bladder is the part inside the wing. I'm not sure what an air cell is. I've not heard that terminology relative to BP/W.

The lift capacity of the wing depends on how negatively buoyant the rig is. If you are purchasing a new steel cylinder, it will be a Worthington cylinder (because of where you live, they are the best price), distributed by XSScuba (http://www.xsscuba.com/). You can see the specification for the cylinders here: http://www.xsscuba.com/tank_steel_specs.html.

Experience has taught me that I need 24 lbs to sink my wetsuit. If I use an HP100, it is -2 lbs when empty (always use the empty buoyancy when calculating weight needed or you'll be too light at the end of the dive). My gear, regulator, etc. are approximately -4 lbs buoyant. This means I need another -18 lbs to sink my wetsuit. The steel backplate I'm considering would be -6 lbs. So I need to wear another -12 lbs of lead on a belt. However, the HP100 when full with have -12 lbs buoyancy.

If we review, the HP100 + gear/regs/etc. + backplate would equal -22 lbs. So my wing has to have at least 22 pounds of lift. If my wing only had 17 pounds of lift, the rig would not float at the surface by itself. I want the gear to float if I take it off at the surface.

Now, if I use integrated weight pockets or v-weights attached to the backplate, the rig would be: the HP100 + gear/regs/etc. + backplate + 12 lbs of lead for a total of -34 lbs. In this case, I need at least a wing with 35 lbs of lift.

Bottom line, the lift of the wing should be functional. How much lift do you need? General observation has been that someone diving with an aluminum backplate, using an AL80 cylinder wants a 17 lb wing. Someone diving steel cylinders with a steel backplate wants a 30 to 40 lb wing. When you start getting into doubles you might need 40 to 60 lb wing (bigger the cylinders equals more lift needed).

A good dive shop will be able to help you figure this out. Other option is figure out how much wing you need without the extra lead, get a wing to handle that and wear the lead on your waist.

bennerman
11-29-2010, 21:21
HOG 38Lb Bladder discounts on sale HOG (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=HOG38LbWing) Bladder
HOG 58Lb Air Cell discounts on sale HOG (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=HOG58LbAirCell) Air Cell

FoxHound
11-30-2010, 09:18
Those 2 wings are double tank wings, the 38 is ideal for double al80s and the 58 would be fine for twin steel 130s. The max you would want for single tanks is 35 and that would be good for a single large steel.

If you wanted HOG then this is what you would want for a singles setup:
HOG 32Lb Wing discounts on sale HOG (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=HOG32LbWing)

Big thing with BP/Ws is that no wing will be good for singles and doubles. you would need one for each AT LEAST.

Some other shops to have a look at are Dans dive shop in st catherins, they have an online store and Matt is really helpful. They carry a full line of BP/W products.

Northern Tech Diver in kingston is great, they dont have an online store but can get you what you need, the specialize in DIR style stuff.

Another thing you can do is check out ontariodiving.com and pick up some used stuff, post in the WTB section and read the classifieds, you can get some really good gear there

Dive tech in mallorytown carries just about everything under the sun and can get you what you need.

FoxHound
11-30-2010, 10:50
I gotta disagree with having enough lift to float ur gear on the surface without you in it. Thats not really what a BC is for. A BC is there to compensate for change of weight in gas, and the material that compresses at depth (ie the neoprene compressing) That is to say your lift capacity should be enough to make you neutral, at depth, at the first of your dive where you are the most negativly buoyant due to suit compression and the weight of your air.

So it takes 24lbs to sink your wetsuit, your gear provides -12lbs (500psi tank) so you need 12 in lead.......ok so can now just barely get under the water after doing a weight check....cool. so at the end of the dive with 500psi left you will be almost neutal buoyant and need very little air in the BC to stay on the surface. with a full tank you now have an extra 10lbs. The average 7mm wetsuit will compress and lose about 8-12lbs of lift by the time you hit 100ft. So the minimum amount of lift your wing would to provide is 18-22lbs. Throughout the dive and as you get shallower you will require less and less lift.



Now to complicate things even more, add a drysuit in. A drysuit generally will keep its same buoyancy characteristics at any depth but what you do have to take into consideration is what happens when you have a catastrophic flooding and you suit looses all buoyancy (highly unlikely as even with some flooding you keep some buoyancy)


IMHO if you want your rig to float on the surface you should be wearing a weight belt. If not you are going to put a wing much larger then you will ever need because you are negating the added boyancy that your wetsuit would create

scubadiver888
11-30-2010, 12:30
I gotta disagree with having enough lift to float ur gear on the surface without you in it. Thats not really what a BC is for. A BC is there to compensate for change of weight in gas, and the material that compresses at depth (ie the neoprene compressing) That is to say your lift capacity should be enough to make you neutral, at depth, at the first of your dive where you are the most negativly buoyant due to suit compression and the weight of your air.

So it takes 24lbs to sink your wetsuit, your gear provides -12lbs (500psi tank) so you need 12 in lead.......ok so can now just barely get under the water after doing a weight check....cool. so at the end of the dive with 500psi left you will be almost neutal buoyant and need very little air in the BC to stay on the surface. with a full tank you now have an extra 10lbs. The average 7mm wetsuit will compress and lose about 8-12lbs of lift by the time you hit 100ft. So the minimum amount of lift your wing would to provide is 18-22lbs. Throughout the dive and as you get shallower you will require less and less lift.

Now to complicate things even more, add a drysuit in. A drysuit generally will keep its same buoyancy characteristics at any depth but what you do have to take into consideration is what happens when you have a catastrophic flooding and you suit looses all buoyancy (highly unlikely as even with some flooding you keep some buoyancy)

IMHO if you want your rig to float on the surface you should be wearing a weight belt. If not you are going to put a wing much larger then you will ever need because you are negating the added boyancy that your wetsuit would create

If I have to take my gear off at the surface (make some adjustment, untangle myself, etc.) I don't want to be struggling with keeping it afloat. I want to be able to float the gear.

For some shore entries, I want to be able to put my gear in the water, get down the slope, put my fins and gear on in the water. If my gear won't float without me in it, this is not an option.

For some boat entries, I want to be able to take my gear off and hand it to someone on the boat. In rough seas I have taken the gear off and used it as a flutter board. I hold onto the gear, some on the boat grabs my gear. Once them have a good grip on it, I let go of my gear and grab the line off the boat. Once they have my gear in the boat, I get them to help me get in the boat. I've had some really good dives off boats that REALLY weren't made for scuba diving.

So there are validate reasons for wanting your gear to float on its own. I would agree that wearing the weight needed to sink a wetsuit makes more sense. If you put it on the rig you are making it necessary to add more lift to the wing when you really don't need to.

FoxHound
11-30-2010, 12:47
Like ive said in some posts on different threads, its all about personal preference.

I guess what i was just trying to get across was that you dont NEED a wing with enough lift to carry only your gear at the surface. I think the weight on your person is kind of a compromise between the 2, plus it makes it nicer for those lifting ur gear onto the boat. 12 lbs less to lift haha. again personal preference, we all got em haha

bennerman
11-30-2010, 14:10
Those 2 wings are double tank wings, the 38 is ideal for double al80s and the 58 would be fine for twin steel 130s. The max you would want for single tanks is 35 and that would be good for a single large steel.

If you wanted HOG then this is what you would want for a singles setup:
HOG 32Lb Wing discounts on sale HOG (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=HOG32LbWing)

Big thing with BP/Ws is that no wing will be good for singles and doubles. you would need one for each AT LEAST.

Some other shops to have a look at are Dans dive shop in st catherins, they have an online store and Matt is really helpful. They carry a full line of BP/W products.

Northern Tech Diver in kingston is great, they dont have an online store but can get you what you need, the specialize in DIR style stuff.

Another thing you can do is check out ontariodiving.com and pick up some used stuff, post in the WTB section and read the classifieds, you can get some really good gear there

Dive tech in mallorytown carries just about everything under the sun and can get you what you need.

It says it has a built in single tank adapter, though o.o

plot
11-30-2010, 17:38
you can use a small doubles wing with a single tank but you have an issue known as tacoing, basically the wing folds up like a taco and you can't release air from it then as it's trapped in the bladders... not a good thing.

bennerman
11-30-2010, 17:46
you can use a small doubles wing with a single tank but you have an issue known as tacoing, basically the wing folds up like a taco and you can't release air from it then as it's trapped in the bladders... not a good thing.

so basically, since I am beginner and the alternative won't happen with me for a little while, I should get a singles wing for now?

plot
11-30-2010, 18:10
i'd highly recommend it. doubles are an expensive venture anyways, you probably want to put it off for awhile.

FoxHound
12-01-2010, 05:14
Yep a singles wing will do you well.

When it comes time for the switch to doubles, twin 80s are a good starting point, and then moving into steels depnding on the diving you want to do.

At that point a BC with 38-45lbs of lift is great for al80s and with steels you will likely want 50-60lbs of lift.

JustAHoot
12-01-2010, 08:29
godivescuba.com
new Brantford scuba store
not much equipment yet but a great instructor

scubadiver888
12-01-2010, 13:03
godivescuba.com
new Brantford scuba store
not much equipment yet but a great instructor

I was going to recommend bennerman have a look at this shop but when I went to the website it only lists Sherwood Scuba for buoyancy compensators. Doesn't look like they have any technical gear.

bennerman
12-01-2010, 13:50
At 750 dollars for an OW course, I can't imagine how much it'll cost for a BCD. I will stick with the more tried and true dealers

scubadiver888
12-01-2010, 18:53
At 750 dollars for an OW course, I can't imagine how much it'll cost for a BCD. I will stick with the more tried and true dealers

Actually, the tried and true shops might be good at tricking you. You want to make sure everything you are getting. Here is a list of what you should be getting and what other shops charge:

$200 training material, classroom sessions, pool time
$200 open water checkout dives
$??? mask, fins, snorkel
$100 regulator, gauges, BCD, tank (with air), weight belt, weights rental

Optional rental might be (for 2 days):

$24 wetsuit
$24 dive computer
$6 hood
$6 gloves

If you read the godivescuba's website carefully you will see that they list the following:


Insurance
Lifeguard
Instruction
Classroom time
Student kit
Exam
Pool
Check-out weekend
C-card
Equipment use on entire course
Air fills
Mask
Fins
Snorkel
Boots
Weight belt


Now some of this is bogus in my opinion. All PADI professionals are required to have insurance or they lose their teaching status. So insurance is a given for all shops.

All PADI professionals are required to have first aid, secondary care and rescue diver skills. These need to be recertified on a regular basis. Without them, they lose their teaching status. So a lifeguard is not necessary. Now if the lifeguard is separate from the teaching staff, this could be good. Personally, I'd prefer if they had a DM as well as the instructor but kept the student:instructor ratio at to 8:1 (or better).

So items 1 and 2, everyone includes or something equivalent. Items 3-6 would be your basic OW course for $200. Items 7-9 would be the checkout dives for $200. Items 10-11 would typically run you $120 to rent. So the question becomes, are items 12-15 worth $230?

$40 to $100 Mask
$30 to $100 Fins
$5 to $60 Snorkel
$40 to $100 Boots
$10 Weight belt
$125 to $370 total

Depending on the equipment he is selling you, it might be worth $750 for everything. If he is selling you the bottom of the line everything then it is overpriced. If all his equipment is fairly good to good then you are getting what you are paying for.

bennerman
01-08-2012, 19:13
Found a pair of tanks in the classifieds for 100 dollars. He said they haven't been tested in 10 years, but he always has them full when he stores them, and would give me a refund if they didn't pass testing (though depending on their weight and value, I may just see how much they can get me for scrap).

http://imgc.classistatic.com/cps/kjc/111229/162r1/8637612_19.jpeg

They look a little rough, but it mostly looks superficial on the outside. The plan is to seperate them and use them as singles, and I asked him if he would knock 25 bucks off the price. Bearing in mind that he will refund them, but will not reimburse me for the actual testing, should I ask my parents for them for my birthday?

Edit: on inspection of the photo, it doesn't look like the manifold can even be detached, but I will look around at other setups to see if I am just not understanding how the connect

bennerman
01-08-2012, 19:26
As well, if I get 90% of the section questions correct in the manual, then I should pass the Open Water Exam no problem, right?

navyhmc
01-08-2012, 20:11
I'd start with getting a new single AL80. Just saying. Leave the vintage stuff for later.

bennerman
01-08-2012, 20:13
I'd start with getting a new single AL80. Just saying. Leave the vintage stuff for later.

I use an absurd amount of weight, so I am hoping for steel, but I will talk to Rick when he comes by for my exam. I'm apprehensive about that though because I almost feel like I am slapping him in the face by not buying from him, but I just can't afford it (I can't even afford to buy my stuff from Scuba Toys). The only way I can justify buying gear at all is that it'll knock a few bucks off rental fees

Also, "just saying" makes it seem like you don't expect me to look at your advice, when this forum's advice is one of the most important factors in this to me (and my sentence structure just made me cringe)

cgvmer
01-08-2012, 22:44
Bennerman, When I started diving my son started with me, then my other son started to dive, then my daughter. So when I buy equipment I buy for the four of us which I can't normally afford. So I did buy a significant amount of used gear from ebay, craigslist, this forum. This includes Blue H bp/w for one son, and D/R transpac harnesses all for less than $300 you just need to be careful with your gear selection. As for tanks, I picked up a pair of hp120 steel tanks in hydro for $250..it took time but it worked. I did buy new regs from ST on sale of course.

FoxHound
01-08-2012, 22:55
Same, Majority of my tech gear when I started was picked up used, then I funded the purchase of my sidemount rig, selling my used back mount stuff. Its a circle, works out well especially when you are just starting out. If you are looking for steel tanks, you can pick up some good used ones for a decent price. Id go to ontario diving and post up a wanted post in their gear forum, there are a lot of folks in our area with gear to pass along.

navyhmc
01-09-2012, 00:58
What I'm saying Benner is to forgo the vintage stuff - even if it's somewhat cheap for newer, modern gear. That set up for instance could be low cost, could pass a hydro (being steel, if in good shape inside I have no doubt it will) etc, but youre talking a circa 58-70 double set up with a gas fitting manifold that is a pain in the butt to reconnect and has to be done absolutely right or it will leak. Not to mention that parts to rebuild are pricey and finding someone to work on it is getting harder and harder to find. Splitting them up for singles would be smart and it looks like they are the 3/4" so you need ot get a couple of new valves - I'd recommend Thermopro 232 bar with inserts. Also, full when stored for 10 years is not necessarily the best way to go. So that concerns me.

A new AL80 is ImHO a good way to start out as they are an industry standard, they're fairly cheap and easy to get. A new tank means you know it's entire history and don't have to guess what type of issues there have been. While the rig may seem inexpensive to begin with could be a nightmare of expenses with time.

Just saying in this case was an apparent failed attmept at humor.

scubadiver888
01-09-2012, 09:00
Found a pair of tanks in the classifieds for 100 dollars. He said they haven't been tested in 10 years, but he always has them full when he stores them, and would give me a refund if they didn't pass testing (though depending on their weight and value, I may just see how much they can get me for scrap).

http://imgc.classistatic.com/cps/kjc/111229/162r1/8637612_19.jpeg

They look a little rough, but it mostly looks superficial on the outside. The plan is to seperate them and use them as singles, and I asked him if he would knock 25 bucks off the price. Bearing in mind that he will refund them, but will not reimburse me for the actual testing, should I ask my parents for them for my birthday?

Edit: on inspection of the photo, it doesn't look like the manifold can even be detached, but I will look around at other setups to see if I am just not understanding how the connect

First, I agree with Navy, skip the vintage stuff. In the long run it will probably cost you more. Getting valves for some of the old tanks is difficult, expensive or impossible. Scrap steel is pennies. I saw them on craigslist and passed on them.

An AL80 is a good place to start. If you get into technical diving they can still be used. Your back gas will be steel cylinders but slinging an AL80 isn't out of the question. Additionally, if you don't get into technical diving, there are plenty of guys in your area who will buy the tanks from you. You can then use the money from that sale towards a set of steel tanks. I do understand wanting steel tanks. For our area and the amount of exposure suit we wear, steel makes a lot more sense.

Essentially, if the tanks are good they tend to cost almost as much as new tanks. If there are issues with the tanks, you'll see them selling for a low price. Sometimes the issue is just that you need to know how to maintain them and where to get parts. But if you don't, they could become scrap metal. You might have noticed a LOT of pre-1989 AL80 tanks for sale. They are the bad alloy and really you are buying scrap metal.

Another thing to think about is renting. Do you REALLY need to own your own tanks? A lot of places do an air fill for $7 or you can rent a full tank for $10. This means you are paying $7 for the air and $3 for the tank. A new HP100 is going to cost you around $450 after tax. You can rent a tank essentially 150 times for that kind of money. Add to that the cost of visual inspection and hydrostatic testing, and owning a tank might not make a lot of sense. Maybe in a few years time you can consider buying a tank. Take your time and look for a used steel tank. However, even a used GOOD steel tank is going to cost around the same price as a new AL80.


As well, if I get 90% of the section questions correct in the manual, then I should pass the Open Water Exam no problem, right?

The OW test is designed to see if you are prepared for diving. It is not meant to trip you up. If you get less than 70-75% then an instructor might have some concern. If you miss a few questions the instructor should go over things and make sure you understand the correct answer. Sometimes you get things wrong because you are too conservative or the questions aren't worded correctly. Regardless, if you do well on the knowledge review, you will do on the exam.

cgvmer
01-09-2012, 15:44
Navy I was not assuming your reference to vintage meant to stay away from used, and when I said used the gear I picked up appeared about 5 years old which I don't count as "vintage". The last things I bought were tanks, mainly as you said since you can usually rent them cheap. I decided I wanted to do some local diving and thought having my own tanks would make that easier, not necessarily cheaper.

BTW: I have never bought used regs, since from my point of view, they are the most technical of basic required gear. I know if a bcd/bladder is holding air, I can see if there is wear on straps etc these items I feel comfortable buying used.

navyhmc
01-09-2012, 17:06
True cgvmer. 5 years is not vintage, but still keep Caveat Emptor as your motto. The tank Benner was looking at screamed "Vintage!!!"

bennerman
01-09-2012, 21:50
True cgvmer. 5 years is not vintage, but still keep Caveat Emptor as your motto. The tank Benner was looking at screamed "Vintage!!!"

It says vintage in the ad too, I just didn't want to post it in the unlikely chance that one of the local divers on here snatched it up

scubadiver888
01-10-2012, 07:25
It says vintage in the ad too, I just didn't want to post it in the unlikely chance that one of the local divers on here snatched it up

Bennerman, everyone local to you who might snatch these tanks up probably saw the posting on January 2nd, six days before you posted here. I thought you were in Ottawa. These tanks are for sale in Brampton. Are you in the GTA?

bennerman
01-10-2012, 15:40
Bennerman, everyone local to you who might snatch these tanks up probably saw the posting on January 2nd, six days before you posted here. I thought you were in Ottawa. These tanks are for sale in Brampton. Are you in the GTA?

Little souther than that :P