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gNats
11-10-2008, 09:49
Hi everyone,

In reading other posts regarding safety stops, I have a question that wasn't really answered specifically.

When doing a 3 min safety stop, is there a min/max depth you should be at?

At what depth does the 3 min stop not count (because you are still too deep) and what is the minimum depth (from surface) that you should not ascend over?

On a recent dive, I did a 3 minute safety stop at a table that was in 18ft of water, just below the stairs to exit the quarry. I sat my bum on the table and drew in the algae on the table to pass the time.

No Misses
11-10-2008, 09:57
The recommendation is 10-20'.

fisheater
11-10-2008, 10:01
Sitting at a table at 18' sounds like a perfect safety stop to me.

texdiveguy
11-10-2008, 10:06
For a recreational NDL dive safety stop anywhere between 10-20ft. is fine with 15ft. being a nice target. 3-5minutes is great......also remember that this 'time' can be spent slowly diving in this suggested depth range and not just sitting in one spot (assuming the setting your diving allows for this//lake,quarry etc.). These stops are optional in NDL diving BUT very much recommended! Have fun and dive safely. :)

SynCitizen
11-10-2008, 10:09
Here is some trivia that is not trivial....

For those of you who don't know the reason for 3 minutes, it is because that is the average amount of time it takes for your blood to completly circulate through your body 1 time. It is a matter of safety for off gassing and getting rid of the nitrogen accumulation that occurs during breathing compressed gasses.

:smiley20: Safety stops are allways a recommended practice and should simply be a part of your dive planning routine.

Original thread. (http://forum.scubatoys.com/open-water-diver/716-3-minute-safety-stop.html)

ReefHound
11-10-2008, 10:14
10-20 foot as stated. My Suunto starts counting at 19 foot and my Nitek Duo starts at 20 foot. If you drop below the count is suspended and resumes once you get back within the range. In the ocean I tend to stop at the deeper end of the range to minimize buoyancy changes and effects dues to waves and surge. As tex said, make the stop enjoyable. Then you won't feel compelled to get out of there as soon as the computer clears. Something newer divers often overlook is that last 10 or 15 foot ascent. It should be done very very slowly. Too often I see divers make a nice slow ascent to the stop, wait out the stop, then quickly pop to the surface.

ppo2_diver
11-10-2008, 10:49
I've been doing something different for the past couple years. I've been doing 1 minute at 30 feet, 1 minute at 20 feet, and 1 minute at 10 feet. It reduces the chance of bubble growth, as bubbles form more easier from 15 feet to the surface than at 30 feet. Plus, it forces you to control your ascent and focus on slowing down. Which is always a good thing on ascents. :)

gNats
11-10-2008, 14:05
For a recreational NDL dive safety stop anywhere between 10-20ft. is fine with 15ft. being a nice target. 3-5minutes is great......also remember that this 'time' can be spent slowly diving in this suggested depth range and not just sitting in one spot (assuming the setting your diving allows for this//lake,quarry etc.). These stops are optional in NDL diving BUT very much recommended! Have fun and dive safely. :)

I don't know why, but I had this idea in my noggin' that I needed to "be still" during the 3 minute safety stop.

I believe my Suunto Cobra begins the countdown at 20'. I know it shows a ceiling of 10'. I'll have to remember to keep flippering around between that range and enjoy myself.

gNats
11-10-2008, 14:11
10-20 foot as stated. My Suunto starts counting at 19 foot and my Nitek Duo starts at 20 foot. If you drop below the count is suspended and resumes once you get back within the range. In the ocean I tend to stop at the deeper end of the range to minimize buoyancy changes and effects dues to waves and surge. As tex said, make the stop enjoyable. Then you won't feel compelled to get out of there as soon as the computer clears. Something newer divers often overlook is that last 10 or 15 foot ascent. It should be done very very slowly. Too often I see divers make a nice slow ascent to the stop, wait out the stop, then quickly pop to the surface.

2nd Question:

I have this cork thing going between 6 ft and the surface. As I ascend I keep an eye on my computer for ascent rate warnings. As soon as I pass 10', I go to the 2nd bar and 6', I am getting the SLOW warning.

When I reach the surface I've dumped all of the air out of my drysuit and BCD is empty.

Is this an indication that I am underweighted at the end of my dive or experience?

MSilvia
11-10-2008, 14:25
I have this cork thing going between 6 ft and the surface. As I ascend I keep an eye on my computer for ascent rate warnings. As soon as I pass 10', I go to the 2nd bar and 6', I am getting the SLOW warning.

When I reach the surface I've dumped all of the air out of my drysuit and BCD is empty.

Is this an indication that I am underweighted at the end of my dive or experience?
It's an indication you're underweighted. You should be able to arrest your ascent at any point in the dive. That said, with experience you might be able to do that with less weight.

bubbletrubble
11-10-2008, 14:34
2nd Question:

I have this cork thing going between 6 ft and the surface. As I ascend I keep an eye on my computer for ascent rate warnings. As soon as I pass 10', I go to the 2nd bar and 6', I am getting the SLOW warning.

When I reach the surface I've dumped all of the air out of my drysuit and BCD is empty.

Is this an indication that I am underweighted at the end of my dive or experience?

Three things come to mind:
(1) Which wrist to you wear your dive computer on? If you wear it on your left wrist...and you operate your dump valve with your left hand, your computer could be recording your quick hand movements to dump air from your BC. A possible solution is to wear the dive computer on your right wrist.
(2) If you've dumped all of the air out of your wing and your drysuit is vacuum-sealed against your body and your pop up like a cork, then you might need an extra pound or two. You didn't mention how much gas was left in your tank, and that would make a difference in being optimally weighted.
(3) You might want to try making a conscious effort to exhale for that last 5 feet beneath the surface. You may be anxious as you near the surface, which in turn leads to shallow breathing. Invariably, this will cause you to cork. Having good breath control is important at such shallow depths.

Keep practicing. Better buoyancy control will come with experience.

ReefHound
11-10-2008, 14:35
I don't know why, but I had this idea in my noggin' that I needed to "be still" during the 3 minute safety stop.

I agree which is why I stop at the deeper end of the range in the ocean to minimize waves and surge effect. You don't have to be perfectly still and could slowly vary depth within a few feet or so. If you're staying between 15 and 18 feet with no quick movements then you'll be fine. But you certainly don't want to be bobbing up and down quickly which is why you should not tightly grip a mooring line or down line but rather make a ring with your thumb and forefinger so the line can slide up and down freely while you remain stationary. That's assuming there is current and you need the line.

texdiveguy
11-10-2008, 15:47
Great information being suggested in this thread!! :)

gNats
11-10-2008, 16:34
If you've dumped all of the air out of your wing and your drysuit is vacuum-sealed against your body and your pop up like a cork, then you might need an extra pound or two. You didn't mention how much gas was left in your tank, and that would make a difference in being optimally weighted.

On Saturday, my tank was 525 psi when the dive ended. However, I have also noticed this problem with fuller tanks... but, the variables are different.

Those other dives included a 7mm 2pc, which would add its own mathmatics.

What I have been unable to do, is complete two similar dives... where ending pressure was similar and exposure suit was similiar. In looking through my logbook, I realize that I keep tweaking something here or there and that in of itself is probably causing me issues.

Grin
11-11-2008, 08:20
The safety stop varies from person to person. They all work, but I like to tear it down and try to take even the simple "safety stop" and make it as good as I can. I try to do the following, but I don't sweat it if I vary from this.
When I get to 20 ft my computer starts counting down 3 minutes. During that 3 minutes, I try to accend a foot per minute leaving me around 14 ft at the end of that 3 mins. Then I take about a minute to come up to the surface from that 14 ft.
My reasoning is the safety stop is important, but what is just as important(possibly more important) is the accent rate from 20-30 ft to the surface. Doing 3 mins at 20 ft them popping up, is not as good as: Skipping the 3 mins/safety stop and instead performing a nice slow acccent that last 20 ft IMO. Doing both is the real way to go, and why not?. So why not incorporate getting a few feet out of the way during your safety stop, is my theory. Maybe even accend from 20ft to 10ft during that 3 mins if your the "in a hurry" type.
It also gives you something to do and think about, rather than sitting there at 15 ft mindlessly doing what you were taught.

gNats
11-11-2008, 08:47
When I get to 20 ft my computer starts counting down 3 minutes. During that 3 minutes, I try to accend a foot per minute leaving me around 14 ft at the end of that 3 mins. Then I take about a minute to come up to the surface from that 14 ft.


Thanks for sharing, this is great information!

ReefHound
11-11-2008, 09:37
Another point is that you sometimes there is a gaggle of divers all wanting to do their stop on a line at the same time. You may find yourself pushed deeper or shallower by the crowd and just lucky to get in there somewhere. You can resolve this by getting a jon line, then you can do your stop at your preferred depth more peacefully. Here are a few:

OMS Jon Line reviews and discounts, OMS (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=OMS_Jon_Line)
Dive Rite Jon Line reviews and discounts, Dive Rite (http://www.scubatoys.com/store/detail.asp?product_id=DiveRiteJonLine)

CompuDude
11-11-2008, 15:36
The usual suggested depth for safety stop is 15'. Giving yourself a 5' buoyancy swing, that keeps the range as 10'-20', which makes sense and which is why most dive computers use that as the target range.

Personally, I mix it up... I do a minute closer to 20', a minute at 15', and the last minute at 10'. You need to be especially careful of buoyancy with this method, however, because if you go outside the range on the wrong side (over 20', or less than 10'), you can stop the timer.

pir8
11-11-2008, 15:46
The usual suggested depth for safety stop is 15'. Giving yourself a 5' buoyancy swing, that keeps the range as 10'-20', which makes sense and which is why most dive computers use that as the target range.

Personally, I mix it up... I do a minute closer to 20', a minute at 15', and the last minute at 10'. You need to be especially careful of buoyancy with this method, however, because if you go outside the range on the wrong side (over 20', or less than 10'), you can stop the timer.
Air permitting stopping the timer justmeans you'll do a longer stop. As long as you don't stray too far

CompuDude
11-11-2008, 16:04
The usual suggested depth for safety stop is 15'. Giving yourself a 5' buoyancy swing, that keeps the range as 10'-20', which makes sense and which is why most dive computers use that as the target range.

Personally, I mix it up... I do a minute closer to 20', a minute at 15', and the last minute at 10'. You need to be especially careful of buoyancy with this method, however, because if you go outside the range on the wrong side (over 20', or less than 10'), you can stop the timer.
Air permitting stopping the timer justmeans you'll do a longer stop. As long as you don't stray too far

Some computers actually reset and make you start over from scratch if you stray from the target range too far or too long. Point being, if you're playing on the fringes, be mindful that you're close to the borderline. It's not necessarily going to be life-threatening (especially since "safety stops" imply NDLs and therefore are usually, technically, optional) but it certainly could be annoying.

methos
03-24-2009, 09:52
When I go with my friends we usually do the safety stop at around 15' or so

snagel
03-24-2009, 17:09
Here is another option that my dive buddies and I do.

Any dive over 60' we do multiple stops. For example, if we go to 80 feet we will split the depth and do a 2 minute safety stop at 40 feet. Then the traditional 3 minute between 20' and 15'.

Typically, we don't just stop at the 40' stop, just level out before acending further.

S. Nagel

COScubaBob
04-14-2009, 13:54
You should do a Google search on RGBM

Several of the Dive computers like Suunto and Mares are using this algorithm to calculate the stops, etc. on dives.

There are a lot of links when you do the search and most have some good info on the pros and cons of the methods being taught. This link below had a pretty good overview, and Suunto actually publishes a small booklet that the LDS should have to give you for free (if they're a Suunto dealer).


RGBM (http://www.electropc.co.za/WWSubAqua/RGBM.htm)

Since I'm a Chemist and a Physicist, the Physiology science of this is all very interesting!

tnrescuediver
08-23-2009, 20:50
10 - 12 ft

comet24
08-23-2009, 21:46
A safety stop is just that a stop to be safe. I say stay between 10' and 20' and your good.

Smashee
08-23-2009, 22:18
4-7m for us metric bods. 3 at 5 or 5 at 5 is the usual.

cummings66
08-23-2009, 22:26
I vary depending on the dive, but 3 at 15 works as does 1 at 20 and 2 at 10 and then slow to the surface. I usually will do deeper stops starting at 40 to 50 feet depending on max depth, stop 1 minute each 10 feet up until 10 feet where you do 2 minutes. Old thread here though.

navyhmc
08-23-2009, 23:02
Like Snagel, if I do a deep dive, I find the deep stops are a good thing. 100' = 60' and 40' deep stops as well as a 15'-20' safety stop.

CompuDude
08-24-2009, 16:59
I vary depending on the dive, but 3 at 15 works as does 1 at 20 and 2 at 10 and then slow to the surface. I usually will do deeper stops starting at 40 to 50 feet depending on max depth, stop 1 minute each 10 feet up until 10 feet where you do 2 minutes. Old thread here though.

I generally try to do 2min at 20' (or just under) and 1min at 10' (or just over). Oceans move around a lot, and holding a 10' stop for 2 minutes is often tricky... it's safer to do the two minutes at the deeper depth.

The computers are happy as long as you do 15' +/- 5'... so anywhere between 20-10' works.

Plus deep stops, of course, for deeper dives.

DivingCRNA
08-24-2009, 19:10
I gotta say, gNats is so happy that this thread is still in circulation 9 months after she started it very early in her dive career!:smilie39::smilie39::smilie39:

In her defense-she has about 70 dives under her belt in that time, 2 Lake Huron wreck trips, several days at Oronogo, several days at Gilboa, nitrox, AOW, deep and drysuit certs and is now in a BP/W and has really good buoyancy control.

So, for all those afraid of asking questionable question-they will live on forever, but your diving and knowledge will improve!!!

Tassie Diver
08-25-2009, 18:22
I've been doing something different for the past couple years. I've been doing 1 minute at 30 feet, 1 minute at 20 feet, and 1 minute at 10 feet. It reduces the chance of bubble growth, as bubbles form more easier from 15 feet to the surface than at 30 feet. Plus, it forces you to control your ascent and focus on slowing down. Which is always a good thing on ascents. :)
I like your thinking and do a similar thing. But I would consider increasing the stop time at the shallower depths.

Something like: 9m/1min 6m/2min 3m/3min.

As you said, the deeper stop controls ascent, but it has the added advantage of filtering bubbles through the lungs while they are smaller and easier to get rid of. Bubbles existing at 3 metres won't disappear as quickly, but if the rest of the dive is non-provocative, the deep stop will help lots.

Cheers

TD.

navyhmc
08-25-2009, 21:40
I've been doing something different for the past couple years. I've been doing 1 minute at 30 feet, 1 minute at 20 feet, and 1 minute at 10 feet. It reduces the chance of bubble growth, as bubbles form more easier from 15 feet to the surface than at 30 feet. Plus, it forces you to control your ascent and focus on slowing down. Which is always a good thing on ascents. :)
I like your thinking and do a similar thing. But I would consider increasing the stop time at the shallower depths.

Something like: 9m/1min 6m/2min 3m/3min.

As you said, the deeper stop controls ascent, but it has the added advantage of filtering bubbles through the lungs while they are smaller and easier to get rid of. Bubbles existing at 3 metres won't disappear as quickly, but if the rest of the dive is non-provocative, the deep stop will help lots.

Cheers

TD.

+1!!! The big reason for the 3 minutes is that is the approximate time it takes the blood to make at least one if not two complete cycles through the circulatory system. Deep Stops help with this as well.

cummings66
08-25-2009, 21:52
As long as they're not too deep. I find that as an aging adult who still thinks he's young that the deep stops allow me to make more dives per day without feeling tired.

Real effect, similar to what many say Nitrox does for them. Plus, I've dove with NavyHmc and I know he takes the deep stops seriously as do I. It works. Just look at any deco chart or program.