use drysuit or BC for buoyancy?

[awdemeo]

I am new to a drysuit and i use a trilame with a heavy undergarment. I use about 36lbs of weight in it and was wondering if it is better to use the suit for buoyancy or use the BCD and just put enuff air in the suit for the squizz
thanks for your help

 

[masterof0]

A majority of the divers, including myself, use the BC for what it is intended, buoyancy, and use the suit for comfort and only add enough air to remove the squeeze and stay warm. By doing this, the one "challenge" you have is controlling two air bubbles, which, with experience, becomes second nature.

The flip side to this is that there are divers who opt for what I will call the "simplicity" method which is to rely solely on the suit. I call this the simplicity method because it puts you in the position of controlling air in only one location instead of two.

Really what it comes down to is personal preference. The best thing to do is try both methods and figure out which one works best for you.

Generally speaking, if you are properly weighted, adding enough air to remove the squeeze should put you in pretty much neutral position. So you shouldn't have to add much air to either one. If you find that you are adding a lot of air to the suit or bc to become neutral, you may want to take a look at your weighting.

 

[Dive Right In Scuba]

Use the BC. If you use the suit, you are putting a big airbubble in the suit...a big air bubble will move around the suit easier and faster....so if you go head down, it goes quickly to your feet, and your inverted easier because its alot of air. You should only put enough air in your suit to keep the squeeze off and to keep you warm.

Now, when you get comfortable in your suit, and properly weighted, typically the air you need to keep the squeeze of and stay warm, is the same air you need to stay buoyant.....so you won't need your BC for buoyancy anymore....but this can take some time and depend on undergarments and such

Hope this helps It is personal preference though, so I would try both, you will see which is better for yourself

 

[Rick Inman]

Yup. Buoyancy Compensator for, ahem... buoyancy, and dry suit for, ah, keeping dry.

Dynamic instability is when a bubble can move about with difficulty controlling it and cause instability. Which means if you have a bunch of gas moving around in your dry suit, you can have exaggerated trim issues as the bubble moves.

Some agencies teach the use of the dry suit only for buoyancy. But it's my opinion that they do this because they think it's easier to teach, not because it's a superior way to dive.

And yes, if your are weighted correctly, by the time you take out the squeeze, you may not need much gas in your BC anyway.

With that said, sometimes when the water is very cold, I really ramp up the argon volume in my suit.

 

[HisLovelyBride]

Use the BC. If you use the suit, you are putting a big airbubble in the suit...a big air bubble will move around the suit easier and faster....so if you go head down, it goes quickly to your feet, and your inverted easier because its alot of air. You should only put enough air in your suit to keep the squeeze off and to keep you warm.

Now, when you get comfortable in your suit, and properly weighted, typically the air you need to keep the squeeze of and stay warm, is the same air you need to stay buoyant.....so you won't need your BC for buoyancy anymore....but this can take some time and depend on undergarments and such

Hope this helps It is personal preference though, so I would try both, you will see which is better for yourself

Yup. Buoyancy Compensator for, ahem... buoyancy, and dry suit for, ah, keeping dry.

Dynamic instability is when a bubble can move about with difficulty controlling it and cause instability. Which means if you have a bunch of gas moving around in your dry suit, you can have exaggerated trim issues as the bubble moves.

Some agencies teach the use of the dry suit only for buoyancy. But it's my opinion that they do this because they think it's easier to teach, not because it's a superior way to dive.

And yes, if your are weighted correctly, by the time you take out the squeeze, you may not need much gas in your BC anyway.

With that said, sometimes when the water is very cold, I really ramp up the argon volume in my suit.

I am technically a dry suit newby, I started diving dry about 6 months ago. I have about 15 dives in my dry suit. I have to agree with these more experienced divers/instructors. I have a White's Fusion dry suit, which restricts the air bubble from as free movement as in other suits, but I don't want more air than is necessary to relieve the squeeze and keep warm. (I have learned the hard way that not enough air makes it very tight and COLD.)

The first few dives were challenging to say the least. I felt like I was a brand new diver, having to relearn bouyancy control from a whole new perspective. Once I got that the dry suit was my exposure suit and my BC was still for bouyancy, it all fell together.

Be patient with yourself and take it slow. My husband and the best dive buddy in the world, and I did several shore dives so that we could work out the kinks without the pressure that boat dives can pose. If something wasn't working right we just got out and started over. Good luck!

 

[tstormdiver]

I was taught to use the drysuit for buoyancy control by my original instructor. My current instructor teaches to use the BCD for buoyancy. I was able to make the change pretty much seamlessly. As the others have mentioned, using the drysuit for buoyancy control means that you have to try to keep up with a larger & more unstable bubble moving around, which can cause problems. There is also the problem that, in the event of an emergency situation, you may not be able to vent the air fast enough from the drysuit to prevent an uncontrolled ascent. Generally drysuits are a bit slower to exhaust air than BCD's. I will use my drysuit for redundant buoyancy control when doing technical diving (twin steel tanks) & have had to practice this technique, but generally I do use the BCD for buoyancy control & the drysuit to stay warm & comfy.

 

[DA Aquamaster]

Its good to finally see a consensus on this.

Not that there was ever much of a difference to begin with.

Using the suit for buoyancy for the most part works for a properly weighted single tank diver, but runs into serious problems with doubles, stage bottles, or with big changes in insulation without a commensurate change in weight - all of which result in an excessively large air bubble that is hard to manage. Tammy's experiece is common I think where a rec instructor sugests one method (to limit the air volumes being managed to one) while a tech isntructor has to address the realities of larger swing weights and potentialover weighting due to reels, stages, lights, etc.

But both views blend well if you just look at it from the perspective of adding enough gas to the suit to keep the insulation lofted (some people dive with an excessive squeeze that adds nothing and just leaves them cold and at elevated trisk for DCS) and then put everything in excess of that in the BC.

 

[awdemeo]

great i will try using my bcd instead. I have the whites nexus 3 and i was using it to do bouyancy with and it was causing me to go in to rapid assents thanks for the info

 

[masterof0]

great i will try using my bcd instead. I have the whites nexus 3 and i was using it to do bouyancy with and it was causing me to go in to rapid assents thanks for the info

Something else I will offer as I had a few rapid ascents during my first couple of dives is the use of the adjustable exhaust. Initially, I would crank it down so that the air would not exhaust unless I wanted it to. This added a layer on complication to have to manually purge both my BC and my suit. Now when I dive, I only crank it down enough to maintain the amount of air I need at a given depth (which, so far has never been more than one or two clicks). Now as I start to ascend, the expanding air purges on its own (or with a very slight movement of the arm/shoulder).

I offer this because I have recently dove with several new drysuit divers who cranked down the exhaust and struggled to maintain a controlled ascent.

 

[Peter Guy]

This person's perhaps under-educated response to the question of BC vs. Suit is: It depends!

It depends on what I'm doing, how fine a control I want, how does my suit feel, etc. In general, I'm going to use my suit to control my neutrality in the water column and use the BC (wing) to offset the weight of the gas/gear. As I descends, at first, air in the BC offsets the general negativity of everything that's on me -- and once somewhat neutral in a few feet of water, air goes into the suit to fine tune AND get rid of squeeze AND keep me warm AND, perhaps, get my feet floaty if that's what I want.

As I ascend, I try to use my suit to control my position because it is easier to vent than my wing -- and as I get closer and closer to the surface, I have to also vent the wing (remember, it was primary on descent, close to the surface).

It's a process and just depends on what I'm doing. But I do NOT purport to have a good answer to the OP's question.