Feeling Grumpy: Need help controlling ascent rate

[73diver]

Hi Folks,

I went ice diving last weekend with my club and I had one of my usual problems when using my drysuit. When I don't have an ascent line (like a boat mooring or other references) I often have difficulty coming up the water column and making a nice controlled ascent and stop at the safety stop. I know it can be done because I was tending line as a couple of guys my age did it perfectly. It was a pleasure to watch such great control.

Since I can do this skill in my wetsuit I know it is a matter of practice and experience with my drysuit. I have decided that I am going to make frequent trips to the local quarry this spring and practice this skill until I've got it. Any advice from other old divers would be appreciated.

Thanks

 

[tbone1004]

I'm a young diver, but the big question here is are you using the suit for buoyancy or the wing? I know up there you are using quite a bit more air in the suit and if you're just diving an AL80 or single tank of any sort it may be easier to just use the suit which is ok but it will help shed light on what you are trying to do during ascent.

Question 2 is whether or not your dump valve is all the way open or not. One of the nice things with drysuits is they can almost auto dump on ascent if you manage the bubble correctly, this takes a lot of practice and a bit of skill, but with the dump open fully, you can get the bubble to where it is just barely at the dump valve and as you ascent it will automatically dump the excess air maintaining your ascent rate. This is how you are actually supposed to use dump valves on bc's, but about 0.1% of instructors actually know how to do it, and most have never heard how to do it like that.

On open circuit it is a combination of dumping and breath control, inhaling as you dump to counter the lost buoyancy then controlling the exhale so you can slow down the ascent or stop it, just takes practice. If you have access to a pool it is the best place to practice since the pressure differentials are much nastier from 10ft to 3ft than they are from 50ft to 15ft

 

[TSandM]

The key with a dry suit is anticipation. You can vent a BC or wing very quickly if you need to; a dry suit has a much more distributed bubble, and you have to plan ahead to move air up to the dump valve. Venting a dry suit is also much more dependent on maintaining good trim.

For me, at the beginning, keeping the suit quite snug and putting most of the gas in the wing worked, because I could vent the wing. That isn't a good option while ice diving, however, because a squeezed suit is a cold suit. You are going to have to use the tip I got from jonnythan here on SB years ago . . . Inhale, move up a little, and EXHALE. If you stop, all is good; if you don't, VENT. Using that technique, you never move very far off neutral, so you never get up a huge head of ascent steam.

 

[They call me Tater]

Hey 73! I am going to the dark side and will be getting new gear this spring so I would be happy to get in some early cold water quarry dry suit practice in late April or early may. I can't provide any tips, but can offer some practice time.

 

[73diver]

TS&M & tbone-Thanks for the tips. The anticipation, using breathing combined with venting sounds excellent. I will be practicing this technique.

Tater-Always interested in diving with you and I'm mostly retired now so every day is like a Saturday.

 

[Wayne at DiveSeekers]

Yes on anticipation, exhaust valve open/not closed & breathe control. Besides that, try coming up in levels (10' increments) as well. Do not come right up from 60' to 15'. The other issue could also be drysuit, A bunch of suits have bad exhaust valve placement (LOOK BELOW). Valve should be on outside of the bicep not on the top when we are in a horizontal, trim position with arms out in front.




Diver in this photo has trouble ascending in trim and hitting stops due to this exhaust valve placement. Air floats past valve and diver has to twist and turn to force air out, thus control issues.

 

[Diver0001]

If you can control your buoyancy in a dry suit 3 feet from the bottom then you can control it in mid water.

The difference is reference. Near the bottom you have a visual reference to judge if you are moving up or down in the water column. When you're in mid-water you have to find a different reference point. I guess you can sort of describe it as "instrument flying". Keep a better watch on your computer and if you're swimming with a buddy then use each other as visual reference for depth.

At first you might find it easier to be slightly (and I means slightly) negative during the ascent and swimming up while watching the computer. Making some swims in mid water with no reference will help you adjust to that mode. You'll learn to spot things that you never realised were there.... little floaty things .... that you can watch to gauge how well you're holding depth. It starts with getting off the bottom from time to time and making a swim without a solid reference point. Eventually the coin will fall.

R..

 

[eelnoraa]

I agree with TSandM, the key is anticipation. When I want to be real precise about ascent (say in class check out), I do these: Before I start, I make sure I am settle in. By that, I will vent my suit until minimal gas is in the suit, compensate by adding air into wing is needed. Get all air out of my feet. Get neutral. Start ascent by inhaling. As soon as you feel you are moving up, start venting the suit. Vent the wing if needed as well. Stop every 10ft and get settled in again (ie, get neutral, get air out of feet, ....). And repeat.

Visual reference can make thing a lot easier. If in blue water, try to shoot a SMB before ascent. Tight knot every 10ft on my spool, and use that as visual reference.

 

[divad]

View attachment 203033

Diver in this photo has trouble ascending in trim and hitting stops due to this exhaust valve placement. Air floats past valve and diver has to twist and turn to force air out, thus control issues.

That must be why he looks crazy...

 

[Diver0001]

That must be why he looks crazy...

I actually had another theory but I learned to dive in Vancouver in the 1980's and magic mushrooms grew wild just about everywhere....

R..