Safety Stop Depth

[bubbletrubble]

Originally Posted by gNats

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]

Originally Posted by gNats

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]

Great information being suggested in this thread!!

[gNats]

Originally Posted by bubbletrubble

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]

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]

Originally Posted by Grin

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]

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
Dive Rite Jon Line reviews and discounts, Dive Rite

[CompuDude]

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]

Originally Posted by CompuDude

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]

Originally Posted by pir8

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.