BCD choice for drysuit

[mmerriman]

most people I know using a drysuit also use steel tanks. consider the weight of the tank along with weight int he harness. I found (during a class) that a small or extra small Ladyhawk sank light a rock fully inflated with a steel 80, and weights. All this on small people that didn't need much weight. My opinion is an 18# wing won't cut it.

 

[Eric Sedletzky]

What I was taught with a drysuit is that you put enough air in the suit to give loft for warmth and to take the squeeze off, if you still need more lift then you use your wing. The guys I dived with recommended splitting up the lift that way between the suit and wing. BTW, I never had an “official” dry suit class I just learned from friends (one was a tech instructor) and by doing it.
For BC I recommend a heavier backplate with a 30 - 40 lb wing. I see you’re in Reno, so you might be going to Monterey? Backplates give you added weight on your back which is a great thing with drysuits, along with steel tanks. A lot of the bubble will be in your upper back and shoulders so having weight there to offset that suit lift is great.
They’re also simple units and infinitely customizable.

 

[shurite7]

I tried to do a search but didn't see anything on this. My wife and i purchased our first drysuits. Now we are looking at future upgrades to our BCD`s. Is there any design or options to look at that make a BCD work better with a drysuit? Currently she has a Scubapro LadyHawk and I have an Aqualung Dimension I3. Thanks for any input

Both of your BCDs will work fine with a drysuit, assuming they are not too small while wearing the drysuit. I've seen people, up here, use both.

It was briefly touched upon above, there are two schools of thought when it comes to buoyancy and the drysuit:
1. Use the BCD for buoyancy just like you do when diving without a drysuit and add enough air (maybe argon) into the drysuit to keep you warm and avoid squeeze.
2. Use your BCD at the surface to hold you up, while underwater solely use your drysuit for buoyancy.

I've seen people argue until they are blue in the face as to which is best. Neither are wrong or right. My advice is to learn both and use what works for you. he first method doesn't take long to learn if you practice with it. The second method is easier to learn in the beginning. I fall in the first group.

Your BCD needs to have a enough lift to hold you at the surface without additional help. Many, but not all, XS BCDs do not have enough lift with all the weight drysuit divers use. A couple people, up here, have no issues with their small Ladyhawks holding them up when diving with their drysuit. When it comes to weight read John's posting above.

Enjoy your drysuits. It is nice to get out of the water and be dry, especially when it is snowing or just simply cold outside.

 

[Storker]

What I was taught with a drysuit is that you put enough air in the suit to give loft for warmth and to take the squeeze off

And if you dive single tank rec, there's a fair chance that any buoyancy change caused by depth change is countered by taking the squeeze off. The only thing your wing needs to handle is the buoyancy change caused by your tank getting lighter.

Because if you take the squeeze off, your volume and thus your buoyancy is basically the same, no matter if you're at 3m or at 30m.

 

[Gradester]

More great info. Thanks all. I think my current BC will work. I will take the class and do a few dives on it and see how it works but all this info here really gives me direction on what to pay attention to.

That’s what I though? But why would it be different with more than one tank?

 

[Eric Sedletzky]

And if you dive single tank rec, there's a fair chance that any buoyancy change caused by depth change is countered by taking the squeeze off. The only thing your wing needs to handle is the buoyancy change caused by your tank getting lighter.

Because if you take the squeeze off, your volume and thus your buoyancy is basically the same, no matter if you're at 3m or at 30m.

It’s been 16 years since I’ve used a drysuit, but thinking about it you’re right, I hardly ever used my wing. Just taking suit squeeze off, it seems that was enough to stay neutral the entire dive.

 

[Keith.M]

That is my experience too. I dived wet in Monterey for my first ~100 dives. Many of those dives were with buddies wearing drysuits. I always watched and learned. Never took a course though bought the PADI drysuit manual. Picked it up without effort.

But.... I have followed the posts over the years here regarding take off the squeeze and then use your wing... But I find that when I am "properly weighted" Taking off the squeeze is all I need.

If I were to change and want to take off the squeeze but then also need to add to wing, I would think I am carrying too much weight.

My question for those of you that think, drysuit to take off squeeze, wing for buoyancy. Do you feel you have to carry more weight to pull that off?

 

[Storker]

My question for those of you that think, drysuit to take off squeeze, wing for buoyancy. Do you feel you have to carry more weight to pull that off?

I don't¹. But since I want to be neutral no matter whether I have a full tank or a near-empty tank, I need some gas in my wing at the start of the dive.

For me (~3000 surface liters/~100 cu.ft. in my tank and a reserve of 50 bar or some 500 surface liters), that means a buoyancy swing of roughly 3kg. If I eat into that 50 bar reserve, I'll have a slightly larger buoyancy swing (up to some 3.5-ish kg, worst case). So, when I go neutral and horizontal a couple of meters below the surface after submerging I'll have 3-4L of air in my wing, giving it a lift of some 3-4kg/6-8lbs.

As I breathe my gas, I slowly vent my wing until it's essentially empty at the end of the dive. Buoyancy changes due to compression or expansion of my undergarments are basically dealt with just by adjusting the amount of gas in my suit (adding on descent, venting on ascent).

EDIT: This also means that correct weighting in a drysuit depends a little on how tight you like to run your suit. Running the suit too tight can be uncomfortable and may not give your undergarments the loft you need to stay warm, while running the suit too loose means a larger bubble inside the suit and more gas travel as you change position.

¹ Disregarding of course that I might well add a kg or two to my belt in the winter, to be able to keep a little more loft in my undergarments when the water is cold.