Drysuit or BCD which to use for BC

[sibermike7]

Privyet Volodya
Where do you dive in St. Pete? Sea, river, or quarry? Wet or dry?

 

[Bob]

Here is some explanation why most divers feel uncomfortable maintaining buoyancy with a drysuit
BAUE Dynamic Instability FAQ

Good information. That's exactly what my Tech Instructor taught me to do. Balanced rig, minimum weighting and the correct size wing. Use the BC for buoyancy control and minimal gas in the drysuit. There's no good reason to complicate something simple. almtree: Bob

 

[vioch]

Privyet Volodya
Where do you dive in St. Pete? Sea, river, or quarry? Wet or dry?

Hi Mike! I dive in St.Petersburg's Neva (river), Ladoga lake and in different local lakes and quarries.

I don't own wet suit at all, because at the depth 20 meters and below the water temperature is not higher than 4C even in summer, thus all dives are in a dry suit only.

 

[imasinker]

I think the best answer is, "I use whichever is appropriate for the circumstance."

New divers are taught to use the suit, because PADI thinks that managing air in the BC and dry suit at the same time is too much task loading. It's the way I was taught, and the way I tried to dive at the beginning, and it resulted in several ballistic ascents. Diving a dry suit with a lot of air in it requires a fine sense of changes in the suit, an ability to anticipate buoyancy changes, and pretty good control of your position in the water -- and brand new divers have none of those things.

When I took Fundies, I went to the "20 foot squeeze", using the wing for buoyancy and only putting enough air in the suit to retain mobility. I wasn't as warm, but I had BUOYANCY CONTROL! The wing is much easier to dump rapidly, and can be dumped in any position, unlike the suit. This went on for a couple of years, although I did gradually increase the amount of air in the suit, as I got better at anticipating changes.

Then I took a Helitrox class this spring from a well-known technical instructor, who wanted us to use the suit as primary buoyancy control. It felt very strange and led to a bit of wobbly buoyancy control at first, but what I have found is that it is MUCH easier to use the suit for buoyancy control if you are going to be doing something that requires your hands (eg. running a reel). All I have to do to vent my suit is raise my elbow, whereas I have to find a free hand somewhere to vent my wing. However, in some circumstances (such as some cave sections, where you have to swim almost straight head-down) minimizing gas in the suit is preferable.

Now, if you are diving with a lot of gear and starting the dive considerably negative (as technical divers can do), you will not be ABLE to use the suit for your only buoyancy compensation, as the amount of air you would have to put in it would be unmanageable. But by that point in your career, managing two air spaces should be pretty trivial.

So I think I would say that my experiences suggest to me that new dry suit divers should be encouraged to keep as little air in the suit as they can, consistent with maintaining a degree of comfort and mobility, and use the BC as primary buoyancy control. They are used to it, and it's easier to get out of a bad situation that way. As you gain facility with the suit, you can try using more and more gas in it. You will be warmer and more mobile, and with a well-constructed suit, may find that it's actually easier. In the process, you'll identify a point beyond which you don't want to go with air in the suit. If you reach this point while doing single-tank diving, you are probably overweighted.

Bang on.....

 

[sibermike7]

Hi Mike! I dive in St.Petersburg's Neva (river), Ladoga lake and in different local lakes and quarries.

I don't own wet suit at all, because at the depth 20 meters and below the water temperature is not higher than 4C even in summer, thus all dives are in a dry suit only.

So all your dives are deeper then? Just curious? Anything worth a trip to St. Pete? We are not far away being in Tallinn.

 

[sibermike7]

Let me re-phrase that! Anything interesting diving wise!
I realize that that St. Pete has a lot of interesting things.

 

[vioch]

Let me re-phrase that! Anything interesting diving wise!
I realize that that St. Pete has a lot of interesting things.

Sent you PM

 

[rlc5925]

I use my drysuit for buoyancy as much as I use my BC for warmth.

Think this sums it up nicely

 

[Tomeck]

I use my drysuit for buoyancy, except for technical diving, because the equipments for technical diving are too heavy to equilibrate only with drysuit.