Buoyancy vs Squeeze Relief

[The Kraken]

OK, as much as I don't want this to take off into the nether worlds of differing discplines of teaching, etc, I know it's going to.

Those of you that know me, via the board, know that I'm not a troll.

Anyway, here goes . . .

I am a very, very, very new dry suit diver.

Before I purchased my dry suit I researched all that I could about using the differing buoyancy characteristics of the B/C and dry suit for buoyancy and squeeze control.

When I made my first couple of dives in my dry suit I noticed that once I started to descend I needed to add air to the dry suit to offset the squeeze. But once at the bottom, I added added just a little bit of air to my B/C to become neutrally buoyant.

As I ascended and descended via breath control the dry suit would vent and then I would have to add a tad if I went deeper.

I guess the question is this . . . if one is properly weighted, where does squeeze control end and buoyancy control begin using the dry suit.

It seemed to me that the changes in buoyancy were so negligible that it really didn't make a whole lot of difference.

Once again, I'm very new at this, so please bear with me.

Thanx . . .

. . . and let's keep it friendly.

the K

 

[ChrisA]

I am right there with you, new drysuit diver. After trying one a few times I just bought one, so with this disclaimer of limited experiance....

I think if you add just enough air to the suit to cancel the squeeze you will _almost_ as a byproduct of that effort have correct bouancy.

My reasoning is that the reason you get heavy at depth is because the exposure suit compresses (either the air inside the drysuit compresses or the neoprene wetsuit foam compress) if you cancel this by adding air you don't get heavy at depth. OK there are other effects like breathing 5 pound of air out of the tank I'm thinking that the air you put into the suit is almost the same as the air you would have had to put into the BC, so it justworks out.

OK, as much as I don't want this to take off into the nether worlds of differing discplines of teaching, etc, I know it's going to.

Those of you that know me, via the board, know that I'm not a troll.

Anyway, here goes . . .

I am a very, very, very new dry suit diver.

.....

I guess the question is this . . . if one is properly weighted, where does squeeze control end and buoyancy control begin using the dry suit.

It seemed to me that the changes in buoyancy were so negligible that it really didn't make a whole lot of difference.


the K

 

[markfm]

The following are just questions -- you know I'm a newbie, did combined OW/DS this past Spring.
Are you partially closing the vent valve at depth, so it doesn't keep exhausting with minor depth changes? I do that, then open it fully prior to ascending to the safety stop.

Degree of squeeze seems to vary a bit from suit to suit. I use an ND DiveMaster neoprene, it seems that if I just offset squeeze, then use my BCD for overall buoyancy, life is good. This, I believe, may be contrary to the PADI DS course, which IIRC says to just use the suit underwater, but it felt more "natural" to use the BCD.

It's absolutely critical to have that vent valve open before ascending, however

 

[MarkH]

OK, as much as I don't want this to take off into the nether worlds of differing discplines of teaching, etc, I know it's going to.

Those of you that know me, via the board, know that I'm not a troll.

Anyway, here goes . . .

I am a very, very, very new dry suit diver.

Before I purchased my dry suit I researched all that I could about using the differing buoyancy characteristics of the B/C and dry suit for buoyancy and squeeze control.

When I made my first couple of dives in my dry suit I noticed that once I started to descend I needed to add air to the dry suit to offset the squeeze. But once at the bottom, I added added just a little bit of air to my B/C to become neutrally buoyant.

As I ascended and descended via breath control the dry suit would vent and then I would have to add a tad if I went deeper.

I guess the question is this . . . if one is properly weighted, where does squeeze control end and buoyancy control begin using the dry suit.

It seemed to me that the changes in buoyancy were so negligible that it really didn't make a whole lot of difference.

Once again, I'm very new at this, so please bear with me.

Thanx . . .

. . . and let's keep it friendly.

the K

Being a rebel out to kill myself, I don't use my BC at all underwater. I use my drysuit for buoyancy (which takes care of squeeze as well). That way I just have one bouyancy device to worry about. I use my BC for swimming on the surface and as an emergency backup underwater. I think I hear the PADI police kicking down the door, so I have to go and reload.

 

[MarkH]

I hear the PADI police kicking down the door, so I have to go and reload.

...Or is it the anti-PADI, Tech police... Sometimes religion is so confusing.

 

[scubadobadoo]

Depends on the thickness and type of undies you are using too as well as how deep. I find that as I dive more in my dry suit I let it squeeze me more and more and barely need to off set the squeeze that I used to perceive was a problem. I now use my BC alot more and my dry suit less if barely at all unless diving really deep. I have found that this leads to me adding less air to EVERYTHING during a dive meaning better control and less fussing.

 

[Canadian_Diver]

I guess the question is this . . . if one is properly weighted, where does squeeze control end and buoyancy control begin using the dry suit.

It seemed to me that the changes in buoyancy were so negligible that it really didn't make a whole lot of difference.

Well, I myself don't use my BC when dry diving except on the surface.

Some consider this unorthodox or unsafe. I disagree. My weighting is such that by the time I put enough air in my suit to take the squeeze off, I am also neutrally bouyant. I always leave my purge valve in the auto position except at the beginning of the dive when I am on the surface.... this is to prevent water from entering the suit through the valve.... I squeeze as much air as I can out of my suit before getting into the water.

I hope I understood the question and answered it the best I can.

 

[JeffG]

...Or is it the anti-PADI, Tech police... Sometimes religion is so confusing.

all of you are Shirley going die (and quit calling me Shirley)...probably not from your drysuit...but it is inevitable none the less.

It has nothing to do with your undies....it has to do with proper weighting and the size of your tank. The bigger the tank, the bigger the swing weight, ergo the bigger the "ball" of gas in your drysuit (If you are overweighted ... you have artificially exaggerated the bubble). A drysuit is not as good as a BCD for managing that gas bubble.

But, with most recreational setups I don't think its that big of a deal, and in truth, IMO its a good skill to know (using your drysuit as a bcd), but once you start using bigger tanks and/or doubles its doesn't work (using your drysuit as a bcd) and hopefully you have not ingrained some bad habits.

 

[MarkH]

Being a rebel out to kill myself, I don't use my BC at all underwater. I use my drysuit for buoyancy (which takes care of squeeze as well). That way I just have one bouyancy device to worry about. I use my BC for swimming on the surface and as an emergency backup underwater. I think I hear the PADI police kicking down the door, so I have to go and reload.

By the way, don't think I'm pumping half my tank into my drysuit. Just a little shot now and then works fine.

 

[matt_unique]

I add air as I descend until my suit is comfortable then shift to adding air to my wing. If I am colder I add more air to my drysuit for warmth for a given depth (and shift that volume from my wing). I dive neo dry so if I used my suit only (particularly at a decent depth) I would be managing a large bubble in the suit which is not comfortable.

--Matt