Safety stop body position

[LowDrag]

That is not off gassing. Off gassing is at the tissue level.

I guess off gassing is the wrong term. What I mean is...with your lungs under less pressure your nitrogen level would still drop the same as if you were horizontal wouldn't? I mean, the gas exchange takes place in your lungs so whether your lungs are above your lower extremities or even with them it seems to me that it would be the same wouldn't it?

 

[Nemrod]

Well see, here is the thing:

1. You should always be horizontal throughout your dive unless a specific need requires different.
2. On a safety stop horizontal places the entire body at the stop depth.
3. On a safety stop horizontal is more conservative of space so more divers can pack in.

N

 

[Peter Guy]

Back to the OP's question -- In many of the PADI publications, it is stated that vertical ascents and descents are preferred because one can fin to hold position. In addition, if one is holding onto a line or bar for the safety stop, vertical might be an easier position to hold. The sad reasoning for this is that the horizontal position requires the diver to be more or less neutral in the water whereas the vertical position can be easily held while negative -- all you have to do is "kick up."

Of course there is just one tiny downside to this method -- if you get task loaded or otherwise distracted and slow down or stop your kicking, guess what, you sink! Or if you add just a little too much air to your BC and start rising but don't stop kicking, guess what, you shoot up like a rocket.

If you are neutral (and not in a dry suit) it should be easy to maintain your stop in any position, up, down or sideways. If you are not able to maintain neutral buoyancy and need to make a safety stop, probably best to do so vertically so that you can maintain your position by kicking yourself into the stop. The real key is to work at getting the ability to be neutral and then you can decide for yourself what is the best position for you at that time under those conditions.

 

[Nwcid]

Delete

 

[DivemasterDennis]

Despite the posts above by people I respect, I think the answer to the question should be "it doesn't matter. Vertical head up is fine. So is horizontal, face down, or up. I have been vertical head down, usually related to getting a picture or just playing around. The key is to be aware of other people and things ( including boats ) that are around you, and when you do your final ascent, to watch where you are going. Those who advocate a "right way" or correct position for hovering during a safety stop really have no basis for it, except that someone once told them what they are telling you.
DivemasterDennis

 

[TSandM]

There is a small theoretical concern about the depth differences between parts of the body, when you are vertical. After all, ambient pressure will be different between your head, your lungs and your feet, which might give rise to some differences in decompression. Nobody has ever been able to prove that this has any practical impact, especially for recreational divers, where gas loading in most of the body is well below saturation.

 

[g1138]

I don't think off gassing has a huge difference between the 5-6ft of your body length. I know plenty of divers (myself included) who can see the boat and diving team just as well horizontal than if we were vertical. It's all about positioning, trim, and a few flashy barrel rolls.
With vertical positioning it is easier to hold a stop theoretically, if you have bad buoyancy control (because you can kick). With horizontal position you have to have good buoyancy control.

In the ocean the anchor line is going to be at least a 45 degree angle more often than not. So at your safety stop depth, if you can't see the boat in a horizontal position, then the viz is probably such that you can't see much at all. So the focus is now on your team which should be right in front of you. You'll be able to see them horizontal or vertical just fine.

I do think body position has to do more with safety though.
My preference is to be horizontal, it's easier to react if need be. Most likely you will need to react and swim forward (say your buddy is having an issue). In a horizontal position you have a roughly 70 degree angle at which you can swim forward, forward-up, or forward-down. So to maneuver towards a buddy you would just have to load a kick then kick or if you're in a DIR position you're ready to just kick.

In a vertical position this angle is only pointed up above your head. To swim forward you would have to pivot yourself, load a kick, then kick. It's maybe a second or two longer to get to your buddy. Plus I find it harder to maintain my depth in a vertical position.

 

[cbm32]

Good grief folks, recreational diving is supposed to be ....... recreational! Who says that most of the dive should be from the horizontal position and WHY? In the right current I LOVE to do most of my dive vertical. I just stand up like I would on land and have an excellent view of everything as I go by. If I want to change my position it is a pretty easy and fast movement for me to get horizontal and fin to where I want to be. Heck it is salt water, not molasses. With no current I sometimes go vertical if I want to just hang there and watch something...like a turtle swimming by or a spotted eagle ray trying to crack open a conch. I am diving for FUN why would I let someone else tell me what position I should be in?

Now maybe my reaction to this is coming partly from the fact that with my spinal cord damage it is more uncomfortable to be perfectly horizontal if I want to look ahead of me but, really, come on folks having fun diving isnt necessarily rocket science.

As for that safety stop, I prefer to do them while moving around looking at stuff rather than being stationary and my buoyancy is good enough that that is seldom a problem. If I have to be stationary it is most comfortable for me to be vertical and so that is what I most often do. The ONLY position I can think of that I would say is a bad idea is upside down finning hard to stay at the right depth and thati s only not a good idea because it means your buoyancy skills are probably such that you shouldnt be in the open ocean anyway. But, if you are vertical upside down because you enjoy it and not just because you are finning and fighting to stay down, have at it and enjoy yourself.

 

[Hatul]

If I'm coming up on a line, any position is fine. If I'm doing a blue-water ascent I prefer being vertical. Here it's easier to be slightly negative and gently fin up. It's just easier to control the rate of ascent this way.

 

[dumpsterDiver]

I think the concerns about offgassing are PURELY theoretical and really not of significant magnitude to make any difference to the recreational diver.

In a dry suit, unless you are hanging on the line, it is far easier to hover in a horizontal position. This is also true if you are using big, negative steel tanks, which will want to pull you over backwards if you are upright.

It is much easier to move forward and back when you are horizontal, so if you are getting blown off the upline, you can get back there more easily from a horizontal hover. Same with being able to assist a buddy, say somebody who has gotten vertigo on ascent.

If there is boat traffic, or if you are coming up through a crowd, you may want to be vertical in at least the last ten feet or so, for safety reasons.

Edited because a post was added while I was writing: Reading that story makes me very, very glad that I trained with folks who would never have signed me off to do staged decompression diving if I couldn't hold a stop -- in WHATEVER position -- within 3 feet, while maskless, sharing gas, or otherwise task-loaded. Your instructors did not do you a service.

Damn you are getting to be a hard ass!

Of course, I completely agree with you, but that sounds like something I would say... and.. I would give it a good chance of being deleted too...