Dry Suit and Buoyancy Control

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coralreefer_1

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Messages
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Location
South Korea
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Hello to you all, and please mods feel free to redirect this post to a more appropriate forum is needed.

I began a Dry Suit specialization with PADI over the last weekend..mainly because it was the only thing I could do in winter.

To make a long story short, I am wondering. The PADI videos and textbook say that once submerged, the dry suit inflation/deflation is used to gain positive/negative/neutral buoyancy rather than the BCD. But I am just wondering why that is.

In this case I am training to use a dry suit so manipulation of its air is par for the course. However I cant help but wonder after this is done and one is certified...what the benefit would be to one more experienced and myself to use the Dry suit inflation rather than the BCD.

It was just my first session in the pool, but I found it way more complicated that it needed to be. Turn X valve 5 or 6 times to open, lift an arm up, lean to one side and bring arm down to bleed air, then turn 5-6 more times to close valve...and all of that done to do basically the same thing as a single button push on my BCD.

SO if dry suits main benefit is that they keep us somewhat "dry"...am I wrong in thinking that an empty dry suit (as in, non-inflated) could be worn more or less only as a shield from water/temps...and I could use the BCD to control buoyancy? Is there some reason to use the dry suit for buoyancy control instead of the BCD that I am not understanding?
 
Eventually you will be comfortable with whatever way works for you. You may even find combinations of both, depending on circumstances, of which there are many variables.

Regarding the valve, you will find a "setting" that allows enough resistance to prevent air from escaping, yet allowing it to vent when you "shrug" your shoulder.

Concentrate on understanding how the suit works, how to anticipate changes, how to avoid "trouble"...then worry about your preferences as to where the air goes.
 
Hello to you all, and please mods feel free to redirect this post to a more appropriate forum is needed.

I began a Dry Suit specialization with PADI over the last weekend..mainly because it was the only thing I could do in winter.

To make a long story short, I am wondering. The PADI videos and textbook say that once submerged, the dry suit inflation/deflation is used to gain positive/negative/neutral buoyancy rather than the BCD. But I am just wondering why that is.

In this case I am training to use a dry suit so manipulation of its air is par for the course. However I cant help but wonder after this is done and one is certified...what the benefit would be to one more experienced and myself to use the Dry suit inflation rather than the BCD.

It was just my first session in the pool, but I found it way more complicated that it needed to be. Turn X valve 5 or 6 times to open, lift an arm up, lean to one side and bring arm down to bleed air, then turn 5-6 more times to close valve...and all of that done to do basically the same thing as a single button push on my BCD.

SO if dry suits main benefit is that they keep us somewhat "dry"...am I wrong in thinking that an empty dry suit (as in, non-inflated) could be worn more or less only as a shield from water/temps...and I could use the BCD to control buoyancy? Is there some reason to use the dry suit for buoyancy control instead of the BCD that I am not understanding?

This is a discussion that is on going amongst drysuit divers - some prefer to use BCD only (maintaining only sufficient gas in the suit to prevent squeeze) and others prefer that the suit is used for buoyancy (with the volume of air being adjusted to suit).

There is no right and wrong (as far as I can tell) so long as you can safely use one or other method. I think the thinking for PADI is that you are only managing one buoyancy device with the suit as opposed to suit and BCD.

My personal thoughts are that having more air than strictly needed in a suit means a larger bubble to manage (spread out over a large length of possibly 5 feet) therefore more likelyhood of issues whereas using the BCD means it is a more compact bubble.
 
You will likely find that it is more difficult to manage the air in the suit compared to the wing (it's not THAT difficult though). So it is generally easier to use your wing for buoyancy control and the air in your suit to alleviate squeeze and enhance warmth. What I tend to do at the start of a dive (with full steel tanks) is to add air to the suit as I descend to ward off squeeze and keep my undergarment lofted and then once I am deeper and the suit is where it needs to be I use the wing for any buoyancy control I might need from that point onward. When I am getting ready to begin my ascent I usually vent some air from the suit first (even if it results in some squeeze) so I am not trying to manage two expanding air pockets at the same time.
 
This topic has been widely discussed, with a lot of heat directed at PADI for their recommendation. You will hear from many people here recommending just enough air in the suit to take off the squeeze, and using the BC for buoyancy control. I think it's certainly an easier way to start out, although in the case of very cold water/long exposures you will need more air in the suit to allow the undergarments to loft properly.
 
....Is there some reason to use the dry suit for buoyancy control instead of the BCD that I am not understanding?

Yes - it is quicker and easier to teach. You are being taught for a fee. The BCD is for buoyancy. The suit is to keep you warm. Use the BCD not the suit.
 
Thanks for the input guys. In the pool i had an uncontrolled ascent issue and it pissed me off more or less. My instructor was having me add air to the suit while at the same time releasing air...and it seemed they were not equal in that the rate of exhaust or my position leaning to this side or pumping my arm was enough to offset the air coming in. I just felt like i had noi control at all. Of course,it was my first time and it was a pool (for whatever reason,i tend to excel at deeper depths than shallow)...and it just made me wonder how vital air inflation in the suit was in terms or real diving after certification.
 
This topic has been widely discussed, with a lot of heat directed at PADI for their recommendation. You will hear from many people here recommending just enough air in the suit to take off the squeeze, and using the BC for buoyancy control. I think it's certainly an easier way to start out, although in the case of very cold water/long exposures you will need more air in the suit to allow the undergarments to loft properly.

I agree. but if you have the right undersuit (DUI, SANTI etc.) you don't need to loft it. Also a neoprene suit should be very near neutral with just a touch of gas which many people see as using the suit for buoyancy when it just shows you are weighted correctly.
 
Thanks for the input guys. In the pool i had an uncontrolled ascent issue and it pissed me off more or less. My instructor was having me add air to the suit while at the same time releasing air...and it seemed they were not equal in that the rate of exhaust or my position leaning to this side or pumping my arm was enough to offset the air coming in. I just felt like i had noi control at all. Of course,it was my first time and it was a pool (for whatever reason,i tend to excel at deeper depths than shallow)...and it just made me wonder how vital air inflation in the suit was in terms or real diving after certification.
The suits definitely exhaust slower than they inflate so if you're doing both at the same time, you're going up. I suspect it was just an example to show you how the vent works but it can definitely be scary taking an unexpected elevator ride. I had one on my third or fourth dry dive and my buddy nearly had a conniption over it. He asked me about a hundred times if I was sure I kept breathing throughout. (He's a very conscientious dive buddy.)

I use my suit for squeeze, not buoyancy, but I don't really use a BC until I'm at about 50 fsw or deeper anyway and I've only done 1 dry dive beyond that depth. Do what works for you and ignore what the book says. If you're more comfortable using the BC for buoyancy, do it that way. If you're more comfortable using the suit, do that. Both camps have legitimate reasons for their preferences and neither is "better" as long as you pick one that works for you.
 
Thanks for the input guys. In the pool i had an uncontrolled ascent issue and it pissed me off more or less. My instructor was having me add air to the suit while at the same time releasing air...and it seemed they were not equal in that the rate of exhaust or my position leaning to this side or pumping my arm was enough to offset the air coming in. I just felt like i had noi control at all. Of course,it was my first time and it was a pool (for whatever reason,i tend to excel at deeper depths than shallow)...and it just made me wonder how vital air inflation in the suit was in terms or real diving after certification.

Maintaining stable buoyancy is always easier when you're deeper, because a few feet (or inches) don't make as much of a difference as they do when you're shallow.
 
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