Drysuit air bubble management help please

[Teamcasa]

I would (and am doing myself) practice with your drysuit with a few more pounds. This practice will help with the run away ascents and once you have the suit buoyancy vs squeeze figured out, you can start reducing the ballast.

 

[24940]

Have you tries ankle weights? They won't stop the air from going to your feet, but it will help you maintain your trim when it does.

Ankle weights make great sense for workouts, but not for correcting trim issues. There are better ways.
When the air gets to be too much at the feet, go vertical to reset the bubble. This isn't a solution to your problem, but it will get you back to where you can control the suit.

An exaggerated back arch can help isolate the bubbles and allow you to transfer gas back and forth. Think of an arched tube, filled 3/4 full of liquid. Gas won't travel to the lower portion of the bend and to the other side without flattening the tube or tipping it to one side or the other.

Use body extension to take advantage of leverage. Extending or retracting arms can have a bearing on trim.

Hang in there, I hated my suit for at least the first 15 dives. Now, I prefer the buoyancy characteristics over diving wet.

 

[JeffG]

Have you tries ankle weights? They won't stop the air from going to your feet, but it will help you maintain your trim when it does.

Why does my nose seem to be twitching?


anyways...never use gear to solve a skill problem.

Ankle weights are not needed.

 

[SteveAD]

A big "sloshy" bubbble in the the suit is most likely an indication of being overweighted. To paraphrase Thal, the suit should be snug, as soon as it starts getting sloppy (sloshy) you should already be dumping air.

 

[24940]

Why does my nose seem to be twitching?


anyways...never use gear to solve a skill problem.

Ankle weights are not needed.

Nice restraint, but you'll five yourself an aneurysm if you aren't careful.

 

[David P]

I do/did have the same problem with my suit. On ascent the air doesn't automatically come out of the dump. I used to try grabbing the valve and pressing the button, that never helped at all. I do sometimes still grab the valve and move it around so that it is at the highest point on my arm (slightly rolled to the right).

Do you ascend horizontally or vertically? Just for fun, try doing a vertical ascent (again leaning to the right) and see if it exhausts better. My suit would vent better if I was vertical but somehow or another I figured out how to deal with it in a horizontal trim.

 

[Jim Lapenta]

Harry, you and I really need to get together and dive. I'm diving a trilam suit and do not have the issues you do and my boots are integrated with the suit. You don't need ankle weights. There are a couple things you might try though. One is what is known as fin keepers. Trident makes em. they help to keep some of the air out of your feet and help the fin straps stay on. I've seen em but don't use em. You can also put a nylon strap around the ankles and snug it up a little. This minimizes air going into the feet. They work but I don't use them either. I use Dive Rite gaiters. They not only help with the air bubble thing but my calfs are grateful for the xtra support. They are also very useful in that my legs are not huge and the suit is a little baggy in that area. the gaiters are a good streamlining tool. I can dive without them as my undies fit pretty well and I don't need alot of gas in the suit but I CHOOSE not to.

I also do not dive al doubles. All my doubles, in fact all my tanks, are steel. I dive lp85's with a steel plate and require no weight dry. And yeah you use the wing for buoyancy and the suit for squeeze but if weighted correctly that little bit of air in the suit makes the wing useage very little. For me anyway. At say 60 ft the air in my suit to offset the squeeze requires just a little bit in the wing. On ascent I do vent some from both but have never had the situation arise where I could not just burp a little from the wing and then raise my arm for the shoulder dump to keep up. And there is nothing wrong with a 10ft a minute ascent. You and I both know what happens when someone comes up too fast. Especially if they have some issues with a reverse block. (I'm fine now BTW no lasting effects, thanks to your superior medical skills). But if you'd like to get together for some dry suit practice let me know. I have a quarry up north of pittsburgh and a lake in Caddis Ohio that would work well. Shallow, say 40 ft max but perfect for this kind of stuff. Summersville is a little far for me and I'm not going into Storm dry. It's over 80 degrees. If you want PM and I'll give you my cell number if you don't have it. I think you do though. I've been doing alot of drysuit stuff lately and I think I may be able to help. I owe you anyway for the reverse block issue you helped me with.

 

[Brewski]

The problem that I am experiencing has to do with the amount of air in the dry suit. When I am practicing kicks, etc., invariably the air ends up in my feet and my trim is badly thrown off.

It apears to me your air bubble is larger than it needs to be. Typically this is caused by excess weight. Try just adding small bursts every couple of feet of descent. I do this instead of adjusting my wing as I find managing a single air bubble is easier than two.

The other problem arises on ascent. If I am coming up from depth (60 to 80 feet), I have a lot of air in the suit that needs to be vented. But I just can't get the air out of my dry suit quick enough. At about 10-15 feet I get an out-of-control buoyant ascent.

Again too large a bubble in the suit. Also how do you adjust your dump valve? My DS instructor advised to open completely then close approx. 5 clicks. Thats a starting point of course you may need to close it more if your dump too easilly, or less if it doesn't vent soon enough.

I find that my suit dumps automatically on ascent, as long as I maintain a heads up position.

I know I am going against the crowd that advocates using the wing for bouyancy and just add air to the suit to reduce squeeze, but I find it easier to manage a single bubble than try to vent both the wing and suit on ascent.

 

[lowviz]

The other problem arises on ascent. If I am coming up from depth (60 to 80 feet), I have a lot of air in the suit that needs to be vented. But I just can't get the air out of my dry suit quick enough. At about 10-15 feet I get an out-of-control buoyant ascent.

It doesn't sound like a gear problem, unless your suit is way too big for you. I will also assume that your weighting is close enough as you seem to be checking properly. You said that you have some trouble reaching your valves with a squeeze but are fine if your suit has a lot of air in it. Everything sounds about right.

I had issues with my DS until I started keeping a moderate squeeze throughout my dive. It was easy for me to lose track of my suit's state of inflation or rate of inflation as soon as the squeeze left. You might be starting your correction way too late. Your arm dump shouldn't have to work very hard. Dive with a moderate squeeze until you get the feel of your new suit. You can add comfort later.

If you have a warm-neck collar on your suit, watch that you aren't getting air around the neck. If your neck-seal burps, the gas will go into the hood. Trying to recover trim will just feed more suit air to your feet. When your hood finally vents, you are left being light footed. A few more holes along the back of the hood's neck (with a hot nail) will fix this.

Avoid adding too many new gadgets for now. Focus on how your suit feels on ascent in its native state. I assume that you are initiating your ascents by finning up slightly. Try dumping suit air right away. If you start to drop, add a bit of gas to the wing. Just keep getting it out of the suit on the way up before it becomes a problem. All of this will become very easy with practice. I wear a thin stretchy Patagonia polyester top and bottom under my thermals and maintain a good suit-squeeze throughout the dive. When it gets warmer, I lose the thermals but my suit still can't get a good enough grip on me through the polyester to pinch.

Regards...

 

[dave4868]

In one lake (50-55 degrees F) I wear my 400gm Thinsulate and require about 25 pounds of lead (with AL80s). In another lake (60-65 degrees F) I just wear thick long johns and about 6 pounds of lead (with AL80s). I use gaiters

The problem that I am experiencing has to do with the amount of air in the dry suit. When I am practicing kicks, etc., invariably the air ends up in my feet and my trim is badly thrown off. I can use even less air in the dry suit to avoid this -- I have heard the advice of the "20-foot squeeze." But that amount of squeeze is pretty intense, pretty painful, and it makes it very difficult to reach my valves, even if I stretch out before the squeeze gets bad. I also get cold with that much squeeze.

I'm surprised the gaiters allow excessive air to shift to your feet, but the first thing I would try is to trim out your tanks and weights more toward your feet while you have a decent amount of air in your legs and feet (less squeeze). I think you may be starting a little too close to a perfect trim balance with too much squeeze on your feet and legs.

A weight belt will be closer to the feet than integrated weights, if that's a factor.

I would try a little more air in the suit so you can trap a bubble over your shoulders, as has been mentioned. That will offset the greater leverage advantage of the air in the feet compared with the air in the wing.

It might seem like the shoulder bubble might shift to the legs, but I find it doesn't happen. One can control the bubble, as was mentioned.

As far as the often-derided ankle weights, I like 'em because I wear thick foot insulation filled with air, and loosely-laced, over-sized Rockboots. My fin strokes are from a bent knee position, so my feet stay elevated and filled with air. The ankle weights prevent rapid shifts of air into or out of the boots. Since I'm trimmed for lots of air in the feet, if the air's going anywhere, it's going to move out of the feet, and that's not hard to manage.

I use my wing for buoyancy, not the dry suit. I put just enough air in the dry suit to reduce squeeze.

Not me. For buoyancy control, I use only the suit (use both a TLS350 and a CLx450) and never my bcd. To seemingly complicate matters, I use lots of insulation which, of course, requires substantial weight. On top of that, I use about 5 lbs extra weight over the bare minimum I would need. My total weight lately has been 41 lbs for 40-degree water. With my heaviest winter insulation, I wear 55 lbs.

I have no problems at all with air shifting. How can that be?

I think part of the reason is that I keep some of my excess air over my shoulders.

The most important reason is probably that my insulation fills out my suit pretty well. When the air tries to shift, it is slowed down going through the insulation rather than over it, and the air doesn't find a place to balloon.

This is true with heavy insulation, but with light insulation making the suit relatively loose-fitting, I sometimes put some air in my bcd and go for more suit squeeze if I have any noticeable air shifting.

Just my observations. YMMV.

Your gaiters should be preventing ballooning and should be slowing down the shifting air, but apparently it's only taking a little shift to throw your trim off.

So why is that happening?

Could it be due to the greater leverage of the air in the feet versus the leverage of the air in the wing? Try a little less air in the wing, where it can't repositioned, and put the air in the suit where it can be repositioned where you want it, such as above the shoulders.

I seem stuck -- very little air in the suit = too much pain , can't reach my valves but no air in my feet. More air in the dry suit = less discomfort, can reach my valves but too much air in my feet. What to do?

How about adjusting your gear to trim out with air already in your feet and more air over your shoulders? That will give you more control, I think.

The other problem arises on ascent. If I am coming up from depth (60 to 80 feet), I have a lot of air in the suit that needs to be vented. But I just can't get the air out of my dry suit quick enough. At about 10-15 feet I get an out-of-control buoyant ascent.

To avoid this I have to ascend very slowly (10 feet per minute), carefully venting both my wing and dry suit all the way up. At times my sleeve is full of air but the exhaust valve just doesn't vent (I dive with the valve all the way open all of the time). That causes me to start a buoyant ascent so I have to manually depress the valve to dump to regain control. I usually completely dump my wing on ascent because the dry suit buoyancy becomes so dominant on even a very slow ascent.

But when I get to 10-15 feet, there is still a lot of air in my sleeve that won't vent (automatically or manually) and I get a runaway ascent to the surface. I pop to the surface exhaling hard with my arm out like "chicken wing" holding down the exhaust valve, all in vain.

The exhaust valves on both of my DUI suits vent very well even in the more demanding shallower depths. They always keep up with the need, despite the fact that I have so much more air in my suit than you or most people. You can figure I've got several gallons-worth of air in my suit in the winter and it still vents quickly enough.

My guess is that your suit air is partially blocked from getting to your valve. It wouldn't hurt to try the duct tape on the nylon fabric to prevent it from getting sucked around the exhaust valve, as was mentioned. The long johns should be venting fine. Do they? If they don't, I'd try servicing the valve.

I have checked that my weighting is correct. I can just barely maintain position at 10 feet with 300 PSI, an empty wing and a full-on dry suit squeeze. So I don't think that I am under-weighted.

I find being overweighted makes it easier to control my drysuit's buoyancy near the end of a dive when the amount of air in it is minimal. 5 lbs extra means easier and quicker adjustments at that point, not to mention being warmer.

It apears to me your air bubble is larger than it needs to be. Typically this is caused by excess weight. Try just adding small bursts every couple of feet of descent. I do this instead of adjusting my wing as I find managing a single air bubble is easier than two.

Harry appears to have carefully adjusted his weighting close to the "minimum" as commonly defined, but it would be interesting to know if his air shifting is still a problem near the end of the dive when he has very little air in the suit.

I find that my suit dumps automatically on ascent, as long as I maintain a heads up position.

I know I am going against the crowd that advocates using the wing for bouyancy and just add air to the suit to reduce squeeze, but I find it easier to manage a single bubble than try to vent both the wing and suit on ascent.

Same here. It becomes second nature just to raise the left arm and vent when needed. So easy. Never a problem.

Just one guy's opinion, of course!

Dave C