Proper (optimal) body position while submerging and ascending in a dry suit.

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

elan

Contributor
Messages
3,605
Reaction score
590
Location
Toronto, Ontario, Canada
# of dives
200 - 499
I"m working on my trim at this moment and I would love to ask you, experienced guys, about what your body position is during accent and submerging. I have clear understanding about how the dry suit works and that the dry suit and BCD valve should be the on the top of the whole system for the air to go out :)

The question is more about most optimal position that you have found for yourself during those 2 stages of the dive.

Well if we have the most optimal position during the dive - horizontal while submerging I usually take the vertical position just let all air out of the suit to get to the valve and while having the valve at on the top of the whole system wait for the air to leave the suit or purge it depending on how much I have. Them lift the bcd valve and purge enough air to be able to submerge while exhaling, then gradually change my body position to horizontal with my knees bent. As I go down I add more air into dry suit to eliminate the squeeze and to BCD to be neutral.

When ascending horizontally as the air in the legs cannot escape and make the boots fattier I have to take more or less vertical position so the air can move to the valve -then purge it and take the horizontal position and repeat the same as soon as i feel the need to purge air.


What is your sequence of actions and may be tips and tricks you have found during learning. :)

Thanks a lot in advance

Serge
 
I have to take more or less vertical position so the air can move to the valve -then purge it and take the horizontal position and repeat the same as soon as i feel the need to purge air.
I'm quite new myself, but I'll give my 2 cents worth.

Getting vertical everytime you need to purge shouldn't be necessary. I have the exhaust valve on the suit closed at descent and bottom and open it before starting to ascent. To get air out of the drysuit I stay horizontal and only shift my left shoulder up abit and bend the arm so that the valve is the highest point. It will then automatically purge. If you have it closed the same should work when manually purging it.

Same with the bcd/wing. Depending on its form you might need to tilt your body abit to get the air to the valve, but you should be able to stay pretty much horizontal and only move the hose above the highest point and purge.

Might help to think one step ahead, paying closely attention to your depth should tell you in advance when you need to get rid of air so that you can purge abit before you feel the need to and will give will give you abit more time to shift your body enough to move the air to where you want.
 
At the surface, I am vertical. Over the first 10-15 feet, I transition to horizontal. Remain horizontal for the dive. Remain horizontal at the safety stop. Transition back to vertical over the last 10-15 feet.

My dump valve is on my left upper arm. To dump air, I roll a little to my right and let my legs sink a bit. Just enough to let the dump valve become the highest point. Dump air as needed.

Also, I use my BCD for buoyancy at depth. I put enough air in my drysuit to prevent the drysuit squeeze.
 
I'm also fairly new and (worse!) did not take a dry suit course. So what I am really, really hesitant to advise you, more reticent than usual. But I can share my experience. First, I able to vent my suit while horizontal. Second, practice helps. Third, trouble with air in the legs seems to be an ongoing concern for many dry suit divers. I don't have a big problem with that, but I know many people do, so you might try searching here on SB for posts about dry suits and air in the legs. Perhaps you'll end up diving with a pair of gaiters.
 
vertical at surface, transitioning to horizontal, adding air to suit, or raising my arm to vent, as necessary for depth changes, exh. valve closed part way (new valve, it may be different with time)

My advice .. air in feet, with a small rise, such as a stuck inflator valve would cause, is potentially very dangerous .. practice recovery methods until your good at them.
I took a good class with a thorough instructor ... my class report http://www.scubaboard.com/forums/advanced-scuba-discussions/260824-padi-dry-suit-class.html ... without it I never would have thought a drysuit could be so difficult in an emegency
 
For a descent I start upright in the water when my head is ~1ft. below the surface, I move to a horizontal position, and remain more or less horizontal for the rest of the dive.

I had issues with air trapped below my knees during ascent when I first started diving with the drysuit, both on the final ascent, and at any point during the dive when moving up substantially. Whenever there is enough air in my boots to be noticeable, I will assume a slightly head up attitude (still mostly horizontal), and straighten my legs. A few seconds in this position is enough to allow the air to move upward in the suit. Be sure to straighten your legs as bent knees will severely restrict the airflow between your feet and the rest of your suit. Initially I had to consciously think about straightening out my legs or I wouldn't do it.

When ascending directly from the safety stop to the surface, I turn my left side up a bit and do the "chicken wing" all the way to the surface. This way the suit is constantly venting and allows me a nice slow final ascent.
 
"I"m working on my trim at this moment and I would love to ask you, experienced guys, about what your body position is during accent and submerging.... <snip>

What is your sequence of actions and may be tips and tricks you have found during learning."
Serge,

There is no "one way", because circumstances may dictate what you need to do. But there are some general rules that apply routinely.

1. Generally speaking, work on descending and ascending in a horizontal position. It comes in handy for lots of things later on, to include safety stops, decompression if and when that is something you consider, and prevention of "runaway suit". Maintaining a horizontal position in the water column is useful throughout the dive, and makes it possible to perform many other related tasks more efficiently or effectively (e.g. photography, navigation, etc.).

2. Dive with your valve open. The entire point of the drysuit is to have sufficient gas in it to provide thermal protection, but not so much gas that control is compromised.

3. Use your drysuit for thermal protection. Minimal gas necessary to provide thermal protection. Use your bouyancy compensator to compensate for changes in your bouyancy at depth. Organizations that teach students to put no gas into their BCs and use their drysuits alone for both thermal protection as well as bouyancy compensation betray a lack of faith in their students abilities to control two separate "air bubbles" (BC and drysuit). Each has a different function, and each ought to be used for the specific function they were designed to perform.

Drysuits are not like BCs in that they cannot easily be "dumped" if you get into an uncontrolled ascent. They have arms and legs, among other features, which makes "dumping" gas from a drysuit different from "dumping gas" from a BC.

If you are in a roughly horizontal (sky-diver-type) position in the water column, with your arms out in front of you, as you ascend your drysuit will automatically vent gas out of the valve. Assuming you can control your rate of ascent - and that you didn't put too much gas into the drysuit to begin with - your drysuit will automatically vent gas throughout your entire ascent - or, if you are in an environment where you must descend and ascend (cave, wreck,) it reduces your task loading.

This may not be the case if you are vertical in the water column. There is no lift in the legs of the suit, (or in the remaining portions of the suit below the valve,) and as gas vents out the valve you begin sinking. So you add more gas. You rise, and the gas vents out the valve. You sink again. Ad infinitum. Trying to actively vent both suit and BC during the ascent is not necessary if you've got the suit to where it's automatically venting as you ascend.

You avoid this sort of annoyance by proper body position.

Hope this helps,

Doc
 
Obviously you will be V when at the surface, as soon as I start to descend I flip over to H, and stay there the entire way untill I am on the surface again. That said, over head environments such as Oil Rigs I go V the last few feet making it easier to see if Im going to bonk my noggen. Im sure I do roll a bit to the right to purge air out of my DS but honestly I am unaware of it. This last year I have been training with some friends for a tech class, We'll go out in doubles and do nothing but practice ascents and descents all the while doing gas switches, shooting bags, sharing air, doing ascents/descents blinded... fortunately the buoyancy part pretty much just became second nature. Kinda funny because untill I read this post and thought about it, I didn't realize that I don't pay much attention to how much air air Im dumping anymore, its all just feel. As for air in your feet, every once in a while I'll do a dive and get too much air in my feet, I wait untill my buddy isn't looking, then get vericle for half a second letting the air migrate up, get back in position, and then keep on swimmin'. Generally we can do out little Tech 1 dives down to 150 look around for 25 minutes or so, and come all the way back up through deco with no air in our feet... just practice.
This however is in no way a suggestion of what to do, just my own personal findings... practice, if I practice a skill that is considered a difficulty of 4 on a hypothetical scale, and just keep practicing that same skill, yeah I get better eventually, however if I can to skill 4 safely and decently well and then I move on to a level 5 or 6 skill, by the time I can do that skill safely that level 4 skill feels like a level 1. I am not saying to push yourself beyond your training by any means, but I find that as I push myself to the next step, the previous step becomes WAY easier.
 
People talk like the valve is either Open or Closed, it has settings. I usually set mine to 4 clicks off closed so it does a controlled venting. You should experiment in shallow (20-30 feet) to determine what gives you the best venting.

Mike
 
I ascend as shown in my profile picture. You just have to be mindful of the gas in your suit, and keep ahead of the bubble growth.

Addressing a specific topic from the OP: I lower my legs every once in a while to get the gas from my feet and lower legs up to the upper half of the suit. This can by done while the rest of the body remains more-or-less horizontal.
 
https://www.shearwater.com/products/peregrine/

Back
Top Bottom