If you are using relatively small single tanks, this is true. If you are diving big tanks, as we do, it may not be. (A full 130 is about 9 pounds negative.)
Drysuit Buoyancy ????????????????????
- Thread starter Newbie100
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
If you are using relatively small single tanks, this is true. If you are diving big tanks, as we do, it may not be. (A full 130 is about 9 pounds negative.)
Darnold9999
Contributor
Doubt that there is a right answer to this for every situation.
My practice is to get enough air in the drysuit to avoid squeeze and keep warm. Then use the BCD for large changes and the dry suit for small adjustments.
I also dive a couple of pounds overweight to allow extra air in the drysuit if I am getting cold. I dive a Fusion and used to dive a trilam.
Typically a dive starts with just enough air in the drysuit to keep warm and air in the BC to check gear on the surface. Empty the BC to go down adding air to the BC to level off at whatever depth the dive is going to start at. If the drysuit starts to squeeze on the way down I will add just enough to fix that on the way down. Often means that I am adding air both on the way down.
From that point on I am using the drysuit to tweak boyancy unless I make a major change in depth in which case I will go to the BC. I don't want the drysuit to get too much air in it because it takes too long to get it back out and its just easier to manage in the BC.
Typically on the ascent I vent from both, but I use a wrist dump so mostly if I am dumping from BC I am also dumping from dry suit.
My reason for the dry suit tweak is simply that it is easier to find the dry suit fill than the BC hose. I tweak a lot to be absolutely neutral mid breath so I can stop breathing (not hold my breath) to be still for photography.
All of this sounds much more complicated than it is - I find that when diving a wetsuit I often reach for the drysuit fill button without even thinking about it for the first dive or two.
My practice is to get enough air in the drysuit to avoid squeeze and keep warm. Then use the BCD for large changes and the dry suit for small adjustments.
I also dive a couple of pounds overweight to allow extra air in the drysuit if I am getting cold. I dive a Fusion and used to dive a trilam.
Typically a dive starts with just enough air in the drysuit to keep warm and air in the BC to check gear on the surface. Empty the BC to go down adding air to the BC to level off at whatever depth the dive is going to start at. If the drysuit starts to squeeze on the way down I will add just enough to fix that on the way down. Often means that I am adding air both on the way down.
From that point on I am using the drysuit to tweak boyancy unless I make a major change in depth in which case I will go to the BC. I don't want the drysuit to get too much air in it because it takes too long to get it back out and its just easier to manage in the BC.
Typically on the ascent I vent from both, but I use a wrist dump so mostly if I am dumping from BC I am also dumping from dry suit.
My reason for the dry suit tweak is simply that it is easier to find the dry suit fill than the BC hose. I tweak a lot to be absolutely neutral mid breath so I can stop breathing (not hold my breath) to be still for photography.
All of this sounds much more complicated than it is - I find that when diving a wetsuit I often reach for the drysuit fill button without even thinking about it for the first dive or two.
Tigerman
Contributor
Just something that struck me out of the blue.. The size of the tank vs body sice would make a difference wouldnt it?
Bigger suit = more bouyancy from removing squeeze or did I just have a brain fart?
Were pretty neutral in the nude and a 130 will weigh the same wether you have a size xxxl suit or a size s was kinda the lightning strike into my (tired) brain
I hadn't thought of it that way, but you are probably right, Tigerman.
I pretty much only use the drysuit to prevent squeeze and the BC/wing for buoyancy.
Some how an old tread, but my 2c after trying a couple of dry suits at the DOG demo day last Saturday:
Dive 1:
(I had zero experience except some reading, the Padi video and the multiple advices from this board) - well, I decided to start with PADI, worrying only about the air in the suit.
It wasn't great at ALL. this combine with pretty bad fins (very buoyant) that I had to borrow to fit these LLLAARRGE rock boots was not really a good experience.
It worked at the end but I had to be always very concentrated on the air, always ready to push one valve or the other, breathing like crazy to compensate, etc ....
Lunch, chats, etc ... Almost every one (in fact everyone) I talked to was saying to use air the suit for warm and control buoyancy as usual with BC.
So go for dive 2, this time I took some Turtle fins (also I had a very good lookingsuit ;-) .
Ok, this is it. Took me 10s to get the buoyancy right (ok decent but probably much better to what I'm having with the wetsuit and yes it was in a pool ;-). I was advised to hold my arm and check how much air was staying around the wrist and in fact, it was exactly the amount of air I needed to feel warm and get ride of the pressure on the suit.
Once I got that figured out, it was very simple, and also realizing that only a few amount of air was in my suit, I was not worrying at all about bubbles getting in my feet .
All was great, and very simple compared to the first approach.
I understand that eventually, you need to know how to do both, and if i take the class, I'll try to get the buoyancy with the suit, but I'm pretty sure I will stay later with the BC, and I think for beginners, it is actually the simplest approach.
Dive 1:
(I had zero experience except some reading, the Padi video and the multiple advices from this board) - well, I decided to start with PADI, worrying only about the air in the suit.
It wasn't great at ALL. this combine with pretty bad fins (very buoyant) that I had to borrow to fit these LLLAARRGE rock boots was not really a good experience.
It worked at the end but I had to be always very concentrated on the air, always ready to push one valve or the other, breathing like crazy to compensate, etc ....
Lunch, chats, etc ... Almost every one (in fact everyone) I talked to was saying to use air the suit for warm and control buoyancy as usual with BC.
So go for dive 2, this time I took some Turtle fins (also I had a very good lookingsuit ;-) .
Ok, this is it. Took me 10s to get the buoyancy right (ok decent but probably much better to what I'm having with the wetsuit and yes it was in a pool ;-). I was advised to hold my arm and check how much air was staying around the wrist and in fact, it was exactly the amount of air I needed to feel warm and get ride of the pressure on the suit.
Once I got that figured out, it was very simple, and also realizing that only a few amount of air was in my suit, I was not worrying at all about bubbles getting in my feet .
All was great, and very simple compared to the first approach.
I understand that eventually, you need to know how to do both, and if i take the class, I'll try to get the buoyancy with the suit, but I'm pretty sure I will stay later with the BC, and I think for beginners, it is actually the simplest approach.
Andy077
Contributor
I had a real problem when i did my dry suit cert, enough to turn me off dry suits completely.
Now, i was probably overweighted, but on the other hand, I could not sink when i did my weight check, so maybe not.
I read the book, and used my suit to maintain buoyancy, but had some leaks around the neck and wrist seals, which led to a loss of air space inside the suit (filled to my knees when vertical)
yes, i realize water is neutrally buoyant, but the loss of air space forced me to overpressure my suit, first opening the relief valve, which I tightened, then blowing though the neck seal every time i added air, letting in more water, and so on.
Had I thought to use my BC, and inflated my dry suit only to the point of eliminating squeeze, I would have been fine, and not really task loaded, IMHO, since the BC is used like always, and only a quick tap on the suit valve from time to time would have been required to take care of squeeze. I think PADI teaches it wrong, personally. using the BC for buoyancy and just inflating the suit to take care of squeeze is no more task heavy than using a BC and wetsuit, and clearing your ears as you descend.
just one mans opinion, but its what I think.
Now, i was probably overweighted, but on the other hand, I could not sink when i did my weight check, so maybe not.
I read the book, and used my suit to maintain buoyancy, but had some leaks around the neck and wrist seals, which led to a loss of air space inside the suit (filled to my knees when vertical)
yes, i realize water is neutrally buoyant, but the loss of air space forced me to overpressure my suit, first opening the relief valve, which I tightened, then blowing though the neck seal every time i added air, letting in more water, and so on.
Had I thought to use my BC, and inflated my dry suit only to the point of eliminating squeeze, I would have been fine, and not really task loaded, IMHO, since the BC is used like always, and only a quick tap on the suit valve from time to time would have been required to take care of squeeze. I think PADI teaches it wrong, personally. using the BC for buoyancy and just inflating the suit to take care of squeeze is no more task heavy than using a BC and wetsuit, and clearing your ears as you descend.
just one mans opinion, but its what I think.
Similar threads
