drysuit techniques and deco stops

Hi all

i have been diving in a drysut 6 dives and all is going well exept some probs, 1st when i ascend i tend to ascend fast and have probs to dump air with valve open? any help also its better for me to dive with little air in the suit - squeeze, is this a problem interms of insulation and i am a tech diver and want to use it form this but i think i will have a problem ascending and holding stops, how many dives did you have in a d suit before attempting a tech dive?

cheers
declan long

You need to start dumping early and frequent. to stay ahead of the air expansion. and you can all so make intermittent stops to allow for the air to migrate up to the hi point I found slow acent and frequent vent works best. The shoulder vent on a drysuit will not dump air like your BP&W / BCD butt dump and corrugated hose shoulder dump.

The key with a dry suit is a) understanding how you have to position yourself to vent from your particular suit, and b) realizing that you have to anticipate buoyancy changes much more vigilantly than you do when diving wet.

I think, in general, that it's easier when learning to keep the suit somewhat squeezed, although if you are diving doubles, be careful that you don't squeeze yourself to where you can't reach your valves. I also found that it worked better, when using both wing and suit, to vent the wing first, until you get up shallow. Once the bubble in the suit has expanded a good deal, it is much easier to vent -- assuming you are maintaining a good, horizontal position.

I can't answer your question about how many dives, because I certified in a dry suit, and it took me a long time to be able to hold shallow stops well. But I hadn't ever learned to hold them any other way, and buoyancy was not a talent. If you are good at holding stops wet, I suspect a little focused practice will get you right back on track.

^^ what she said.

I dump my wing first and dive w/ my valve open so my suit vents mostly on it's own or with a little body roll. If you have good buoyancy control with your lungs, holding the stops shouldn't be an issue. Just need to manage your speed to the stop and make sure you keep the bubble where you want it.

I think it's actually a bit easier to fine tune w/ a drysuit because it dumps more slowly than a wing.

How many dives is a matter of technique and personal ability I think.

Declan,
Some general tips.

First thing you need to do is put as little gas in the suit as you can while being able to breathe easily. If you end up with marks on your body then you have not added enough gas.

Get your weighting right - your descent to 3m should be quite slow. and quicken noticeably as you descend further.

In shallow water (less than 10m) , stop ie do not fin - this will give you a cue on your buoyancy you'll either rise or sink or if all is well you'll be neutral.

I echo the previous poster - think ahead before adjusting buoyancy. If you know you are ascending, dump a little gas from the wing and then wait a second or two - if descending, add a little gas then wait, if the rate of descent continues add a bit more gas wait and practice this until you learn how to stay in control of your buoyancy.

Don't even think of a tech dive in a drysuit until this is second nature to you.

Minimum gas in the suit does affect how warm you will feel but it is more of an issue in colder water than warm - I'd not worry about that right now.

The thing you have to accept for now is that there is a learning curve. Once you get comfy managing the buoyancy swing, try going to 18m and then pay attention to your depth at about 8/9m - this is where a few dives practice will help. Most people I have seen struggling usually find that 8 or 9m is when they lose buoyancy control - it's here you need to concentrate and where what Krawlings said really comes into focus.

One other thing - in shallow water practice changing your trim from horizontal to vertical then vertical to horizontal. Try swimming on your back and at a angle. You need to get used to the air migrating and being able to react to sudden changes.

I'm not a techie but I think what both Rawlings and I have suggested might help you a bit but don't go on a tech dive until you are in control of your suit.

Quick bullet items
1. 20 dives is a better benchmark
2. Dive with a comfortable squeeze, use BC for main buoyancy
3. Stay ahead of it
4. Ascend in 10' increments
5. Check valve position (should be on outside of bicep, not the top)