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View Full Version : Dives vs. Hours



russp
10-22-2007, 08:05
Just wondering why the number of dives is used to judge a diver's experience instead of hours under water. I got thinking about this after doing a few short (less than half hour) dives this weekend to work on weight and tank placement. The total of these three dives was less than either of my previous two dives which were 1:30 and 1:45. I would think time underwater would be more important than how many times we jump in and out of the water.

NitroWill
10-22-2007, 08:10
A lot of people do use hours - although not as common..

I suspect its just easier to count 1-2-3-4 instead of adding 36 43 57 39 on a continuous basis - although computer software now makes this information readily available..

I believe my instructor is now counting his underwater time in YEARS as he just passed 30,000 dives

Capt Hook
10-22-2007, 08:14
A 20' dive for 1 hour and 30 min. might mean a lot less than an 80' dive for 40 min.

ReefHound
10-22-2007, 08:33
Both are important and neither is an absolute measure. As stated above, deeper dives are often shorter dives yet are often more challenging and offer experience not found on a shallow reef dive.

Also most of the learning comes in the first few minutes of the dive, in my opinion. I've spent over two hours on a shallow shore dive and I doubt I learned anymore than if I had spent 20 minutes there. More dives equal more ascents and descents and possibly more exposure to diverse conditions.

Of course, we shouldn't be trying to pump up the dive count by breaking up what should be a single dive into several short dives. Maybe we should calculate quantity of air consumed?

RoadRacer1978
10-22-2007, 08:34
I keep track of both in my long book. As each dive is logged I keep track of total bottom time. I like keeping track of the time for fun. It's fun to tell someone you spent XXXX hours under water this last weekend.

NitroWill
10-22-2007, 09:20
Yes, they are both important - but the logbook with details is most important..

Another problem with hours is this..

If someone has 100 logged dives in a year it shows theyve been a fairly active diver and has been getting some dives in..

But the same person could say they have 50 hours logged and it only be 20 dives or so in nothing but shallow reefs with 1.5+ hour divetimes..

Not saying that that dive isnt important - because each and every single dive is..Just saying that the one with 100 dives might have more diverse set of dives - but only the full logbook can be the judge of that :)

ScubaToys Larry
10-22-2007, 09:26
I once ran into a guy at lake travis, and he was going down to a platform... sitting for 10 minutes, then coming up and going to shore, then he'd take off the gear, put it back on and repeat...

I could not help myself - so I asked what he was doing and he explained he was a bit short on becoming a Padi Instructor so he had to get in 30 more dives, and for their standards a dive was 10 minutes or 1000 psi of air... so he was going to get in 30 dives that weekend.

Scary.... :smiley5:

RoadRacer1978
10-22-2007, 09:31
Gotta love his dedication! LOL

fire diver
10-22-2007, 09:47
he was going down to a platform... sitting for 10 minutes, then coming up and going to shore, then he'd take off the gear, put it back on and repeat...

... so he was going to get in 30 dives that weekend.

Scary.... :smiley5:

That's someone in need of an air hose cutting if ever I heard of one.

Scary that this perosn is probably teaching his same dive ethics to unsuspecting newbies.

FD

fire diver
10-22-2007, 09:54
Yes, they are both important - but the logbook with details is most important..

I agree 100%.

I keep track of both my dives and my hours in my logbook. All three combine to tell the story, only looking at one is squewing the picture.

What I think makes a person a well rounded and experienced diver is one who has dives in many different locations in many types of diving.

Diverecord.com is an interesting site in this respect. It's an online logbook, that databases, sorts and "scores" your dives. If you do the same dive over and over it gives you less and less "points" for it. easy dives get less points than cold, low-vis etc. Of course the scoring isn't perfect, and some people don't like it, but I think it's kind of a neat feature. PLus you can have access to your log anywhere you have internet.

FD

ScubaJ
10-22-2007, 09:54
wow, that is Scary.
Hope I don't ever get him as an instructor. :smiley11:

ReefHound
10-22-2007, 10:11
I don't know what's scarier, that he was logging 30 dives in one weekend by twisting the intent of the guidelines or that he didn't have the sense to just lie and fake the logbook.

Hollywood703
10-22-2007, 12:15
I run both numbers when i log my dives.....Dive number and Total dive time.

cheebaweebie
10-22-2007, 12:22
When tracking my dives I do the same. I never really pay attention to either # though. I, on some weekends will do 10 dives as in spearfishing I will drop to the bottom hang out for a few minutes and shoot what I can then pop up to get to the next site. We went diving for stonies on opening day in florida and I techincally would have logged 10 dives for the day even though I only burnt through 3 tanks and dove 5 bridges in aanywhere from 15-8 ft or water.

ReefHound
10-22-2007, 12:38
When my computer logs several dives on the same tank as a result of extended surfacing, I will merge the dive profiles into one logged dive.

BobbyWombat
10-22-2007, 16:11
Interesting thought. I'll have to start adding up my aggregate bottom time to see what it looks like.

Agree, though, that the logbook is the real measure of experience.

cshel
10-22-2007, 16:19
My log book tracks both dives and total time under water. It's fun to add it up your bottom time and tell a non-diver. They look at you like you are crazy!

cummings66
10-22-2007, 17:30
I'd log a dive if the computer showed it, and if it was for a purpose other than padding a number.

For example, I'd log a dive if I needed to retrieve an anchor but if I just wanted one more to get the 900th dive logged and only had enough air for 1 minute I wouldn't log it, for that matter I wouldn't dive it.

I got to say one thing about the padi guy, at least he was honest enough to "cheat" by the rules and not just make it up. I know several instructors who've done this creative logging, thankfully none of mine have.

CompuDude
10-22-2007, 17:37
Of course, we shouldn't be trying to pump up the dive count by breaking up what should be a single dive into several short dives. Maybe we should calculate quantity of air consumed?

A dive starts when you enter the water, and ends when you exit the water (for more than 5 minutes, should some bizarre situation like that apply). Popping up to the surface and chatting for 6 minutes (just long enough for the computer to click over to a new dive) should could as an extension of the first dive, IMO.

I wish my logging software made it easier to merge two dives into one. I end up just deleting dives and adding notes to the previous one in an effort to keep numbers straight.

Doug B
10-22-2007, 20:23
I don't know what's scarier, that he was logging 30 dives in one weekend by twisting the intent of the guidelines or that he didn't have the sense to just lie and fake the logbook.



I was thinking the same. Look at it the otherway though. He was twisting the intent, but at least he wasn't outright lying.

He could have at least done a "task" during his ten minutes.... continuous mask clearning, or bouyancy, or math flash cards!

plot
10-22-2007, 21:25
same tank, same dive.

new tank, new dive.


why you guys gotta make this stuff so difficult? ;)

CompuDude
10-23-2007, 00:21
same tank, same dive.

new tank, new dive.

why you guys gotta make this stuff so difficult? ;)

And if you're squeezing two 45 min dives out of one tank, with a two hour surface interval between dives? ;)

js1scuba
10-23-2007, 01:10
Hours or Dives? ......

As a new diver the # of dives is more important than the hours underwater. Here is why. It does not take a whole lot of skill to laze around in 30 feet of water on a reef for an hour or more. However break that 60 minutes up into two 30 minute dives and you have not had an opportunity to do two gear set ups, two buddy checks, two entries, two descents, two dive plans, to dives, two ascents and two saftey stops, two exits and two opportunities to learn something new.

After you put in 100 dives in the first year and you are comfortable and well versed in your craft extending the dive time is not out of line.

Keeping the data on BOTH dives and hours is important all around.

IF you were entering rebreather diving then keeping hours and dives is important with the emphasis on hours. A typical CCR dive is 90-180 min so "time" becomes important.

As to the PADI puff trying to rack up dives....... well ..... you get the point.

Cheers

Anne Eastwell
10-23-2007, 01:12
I don't know what's scarier, that he was logging 30 dives in one weekend by twisting the intent of the guidelines or that he didn't have the sense to just lie and fake the logbook.


Oh god, don't tell me that!!! I'm going to be checking dive logs for shop stamps at this rate!

WV Diver
10-23-2007, 06:20
I keep track of both just for fun. I like stats and records I guess. I have never used the total hours for anything practical. Would be a really good way to get an average for your sac rate if you wanted to go to all the trouble of getting the numbers.

plot
10-23-2007, 16:21
same tank, same dive.

new tank, new dive.

why you guys gotta make this stuff so difficult? ;)

And if you're squeezing two 45 min dives out of one tank, with a two hour surface interval between dives? ;)

Get smaller tanks :smiley2:

WaScubaDude
10-23-2007, 17:05
same tank, same dive.

new tank, new dive.

why you guys gotta make this stuff so difficult? ;)

And if you're squeezing two 45 min dives out of one tank, with a two hour surface interval between dives? ;)

Get smaller tanks :smiley2:

Just dive as often as you can. Practice what you can. Enjoy your diving! and stay alive. If I knew it was such a big fn deal I would say "no comment" to number of dives.

Try to think through scenarios and work out your response. Dive on!

plot
10-23-2007, 17:10
starting a dive with a half empty tank isn't necessarily a good scenario.

RoadRacer1978
10-23-2007, 17:14
Depends on what you are doing. In training classes you didn't change tanks every time you surfaced did you? Plan you dive and dive your plan. If you plan for the amount of gas you have and leave room for a margin of safety, why not make another dive with a half empty tank. Im positive, to me it's half full... :)

CompuDude
10-23-2007, 17:16
starting a dive with a half empty tank isn't necessarily a good scenario.

Depends on the dive plan, your SAC rate, and how big the tank is to begin with, eh?

I know several divers who use Steel 63s. If I'm diving an HP130 that's only half full, what's the difference, other than the fact that I paid for one fill and they paid for two?

WaScubaDude
10-23-2007, 17:25
Depends on what you are doing. In training classes you didn't change tanks every time you surfaced did you? Plan you dive and dive your plan. If you plan for the amount of gas you have and leave room for a margin of safety, why not make another dive with a half empty tank. Im positive, to me it's half full... :)

I love the "tank is 1/2 full" argument. You guys make me laugh my ass off.

fire diver
10-23-2007, 20:13
starting a dive with a half empty tank isn't necessarily a good scenario.

I do it all the time. I'll even start a dive with 1000 in my tank. I can easily get a half hour out of that in the 33-40 foot range and still have several hundred psi left. Last year I finally got tired of refilling tanks with 1000 - 1500 left in them. Now I go do a bunch of fun dives with my used tanks on the last day of diving. No since in carrying all that gas back home. If I got time, water and air I can dive.

FD

willardj
10-24-2007, 12:23
starting a dive with a half empty tank isn't necessarily a good scenario.

I do it all the time. I'll even start a dive with 1000 in my tank. I can easily get a half hour out of that in the 33-40 foot range and still have several hundred psi left. Last year I finally got tired of refilling tanks with 1000 - 1500 left in them. Now I go do a bunch of fun dives with my used tanks on the last day of diving. No since in carrying all that gas back home. If I got time, water and air I can dive.

FD
I like the way you think. I hate taking tanks back that have good air in them exp. if it Nitrox.. I use it all.

Aussie
10-24-2007, 15:14
I once ran into a guy at lake travis, and he was going down to a platform... sitting for 10 minutes, then coming up and going to shore, then he'd take off the gear, put it back on and repeat...

I could not help myself - so I asked what he was doing and he explained he was a bit short on becoming a Padi Instructor so he had to get in 30 more dives, and for their standards a dive was 10 minutes or 1000 psi of air... so he was going to get in 30 dives that weekend.

Scary.... :smiley5:

Seen this when i was in Thailand. It is a common act also which is more scary.

Aussie

No Misses
10-24-2007, 15:29
OK here is one for the 1 tank 1 dive crowd. I was doing a shallow dive 15-20 fsw after being out in 80 fsw. I jumped in with my 1/3 full tank. When I had sucked that down to 200 PSI, I switched to a new tank and went back down. Since my SI was so short, my DC counted it as one dive.

P.S. my SAC was the lowest I have ever seen :smiley36:

CompuDude
10-24-2007, 15:37
OK here is one for the 1 tank 1 dive crowd. I was doing a shallow dive 15-20 fsw after being out in 80 fsw. I jumped in with my 1/3 full tank. When I had sucked that down to 200 PSI, I switched to a new tank and went back down. Since my SI was so short, my DC counted it as one dive.

P.S. my SAC was the lowest I have ever seen :smiley36:

Why would your SAC be affected by depth, since it accounts for that by it's very nature?

No Misses
10-24-2007, 15:46
OK here is one for the 1 tank 1 dive crowd. I was doing a shallow dive 15-20 fsw after being out in 80 fsw. I jumped in with my 1/3 full tank. When I had sucked that down to 200 PSI, I switched to a new tank and went back down. Since my SI was so short, my DC counted it as one dive.

P.S. my SAC was the lowest I have ever seen :smiley36:

Why would your SAC be affected by depth, since it accounts for that by it's very nature?

My computer saw my staring pressure @ 1200 PSI. Two hours later it saw my ending pressure at 1000 PSI. As far as it knows, I burned through 200 PSI in 2 hours.

CompuDude
10-24-2007, 15:53
OK here is one for the 1 tank 1 dive crowd. I was doing a shallow dive 15-20 fsw after being out in 80 fsw. I jumped in with my 1/3 full tank. When I had sucked that down to 200 PSI, I switched to a new tank and went back down. Since my SI was so short, my DC counted it as one dive.

P.S. my SAC was the lowest I have ever seen :smiley36:

Why would your SAC be affected by depth, since it accounts for that by it's very nature?

My computer saw my staring pressure @ 1200 PSI. Two hours later it saw my ending pressure at 1000 PSI. As far as it knows, I burned through 200 PSI in 2 hours.

LOL gotcha

No Misses
10-24-2007, 16:00
Ok, I just went back and pulled up the info on this dive.

Working Pressure 3000
Cylinder size 80
Starting Pressure 1710
Ending Pressure 1760
Dive time 62 minutes
SAC rate 0 This should really be a negative number. I breathed 50 psi back into the tank ;-)

plot
10-24-2007, 16:06
You got gills or what?

RoadRacer1978
10-24-2007, 16:07
Lungs of steel putting air back.:smilie39:

Buoyant1
10-24-2007, 20:03
I once ran into a guy at lake travis, and he was going down to a platform... sitting for 10 minutes, then coming up and going to shore, then he'd take off the gear, put it back on and repeat...

I could not help myself - so I asked what he was doing and he explained he was a bit short on becoming a Padi Instructor so he had to get in 30 more dives, and for their standards a dive was 10 minutes or 1000 psi of air... so he was going to get in 30 dives that weekend.

Scary.... :smiley5:


There was a guy on the other forums talking about a dude he dove with frequently that counted surfacing to get oriented as another dive...basically this guy counted it each time he surfaces and then descends! Heck I'm usually worried that my computer is going to count things like that as reperetive dives...during my AOW course we were up then down then up then down...thankfully they all counted as one dive for each module! (made it easier in my computer log!)

Personally, I keep the running tally for hours in my book...

BouzoukiJoe A.K.A. wrecker130 AKA Chuck Norris AKA joeforbroke (banned)
11-02-2007, 09:22
Neither the total number of dives nor the total number of hours means that much. What matters is the amount of recent experience in similar dive conditions.

5000 hours in a quarry at 30-60 feet does not prepare a person properlly for a 20 ft shore dive at Nags Head. Nor does it prepare one for a 120 ft wreck dive 40 miles off the NC coast in 6 foot seas.

Some charter operators here want to see a minimum number of total dives, and at least some recent dives to depth and from a boat. One group I know requires that you have 2 previous dives to at least 100 ft off the NC coast before you can book. Other locations do not count. So to get started you either go with a less strict operator or you go under the supervision of an instructor.

The cynic in me says they just want to make money from tuition. The realist in me says they don't want someone w/o experience to ruin the trip for the others.

BouzoukiJoe A.K.A. wrecker130 AKA Chuck Norris AKA joeforbroke (banned)
11-02-2007, 09:28
I once ran into a guy at lake travis, and he was going down to a platform... sitting for 10 minutes, then coming up and going to shore, then he'd take off the gear, put it back on and repeat...

I could not help myself - so I asked what he was doing and he explained he was a bit short on becoming a Padi Instructor so he had to get in 30 more dives, and for their standards a dive was 10 minutes or 1000 psi of air... so he was going to get in 30 dives that weekend.

Scary.... :smiley5:

This instructor will be qualified to teach the following:

1. Setting up gear
2. Making 10 minute dives to a shallow platform in a quarry.

That's exactly why I got into diving :smilie39:

Puffer Fish
11-02-2007, 10:03
I once ran into a guy at lake travis, and he was going down to a platform... sitting for 10 minutes, then coming up and going to shore, then he'd take off the gear, put it back on and repeat...

I could not help myself - so I asked what he was doing and he explained he was a bit short on becoming a Padi Instructor so he had to get in 30 more dives, and for their standards a dive was 10 minutes or 1000 psi of air... so he was going to get in 30 dives that weekend.

Scary.... :smiley5:

This instructor will be qualified to teach the following:

1. Setting up gear
2. Making 10 minute dives to a shallow platform in a quarry.

That's exactly why I got into diving :smilie39:
Well, at least he was actually making the dives... such as it was...sad that he would do that.. even sadder if PADI accepted it.