Using your drysuit as a BC

[eponym]

I'm happy to hear these thoughts. I'm new to drysuit diving (a dozen dives, six hours down). I've been doing it as taught, not inflating the BC, and I find dumping air on ascent is unpredictable (sometimes dangerously slow).

So I'm planning to work on BC use (vest BC, not BP/wing) while drysuited this week. I don't think the additional task loading will be a problem and I'm hoping to get a lot more graceful on hovers and ascents.

Thanks!
Bryan

 

[eponym]

Errg (embarrassed swallowing sound kermit makes) . . .

Please note I posted before seeing mempilot's hilarious thoughts, so my "I'm happy to hear these thoughts" might sound a bit out of place in the thread . . .

Ah well . . . "You live and learn. At any rate, you live." --D.Adams

 

[mempilot]

Errg (embarrassed swallowing sound kermit makes) . . .

Please note I posted before seeing mempilot's hilarious thoughts, so my "I'm happy to hear these thoughts" might sound a bit out of place in the thread . . .

Ah well . . . "You live and learn. At any rate, you live." --D.Adams

Just screwing around. I believe the bc is the bc, and the drysuit keeps you dry. I put enough air in the suit to keep the squeeze off. I keep myself weighted for neutral buoyancy at 20' at the end of the dive. At moderate depths, I don't need to put any air in the bc. It takes a while to get this all worked out, but with a little patience and experience, you'll get it properly tuned. I love diving dry. Makes the second dive that much more enjoyable.

BTW, I'm glad your question wasn't: Do I use my drysuit as the lift bag, or my SMB? I'm just kidding you know.

)

 

[eponym]

And the image you painted gave me a laugh. Thanks, MEM pilot.

Thanks also for your reference to SMB's. It got me looking around for an acronym definition (turns out I already own one - I even needed to use it once), and in finding that I also found Robert Delfs' "Surface Survival Primer" article. Great stuff. Having been a sailor for many years before being a diver, it's interesting to think about survival from the viewpoint of rising to the surface instead of from the viewpoint of falling overboard.

Best regards,
Bryan

 

[mjh]

I also just keep enough air in my Drysuit to keep "squeeze" to a minimum. My shoulder valve does not dump air very quickly. Also helps to keep you from getting "light feet".

 

[String]

If diving on singles, provided the weighting is correct there is absolutely nothing wrong with using the suit to compensate for buoyancy changes instead of the BC.

If you arent overweighted you wont have a big air bubble moving, wont look like an overweight hippo and usually just enough air to relieve squeeze will see you neutral.

People only get problems if theyre diving overweighted and therefore have large amounts of air in the suit.

This is totally depth independent, from 3m to 60m this rule holds as after all, you're only compensating for compression, nothing more.

All last season i controlled my buoyancy using suit only and had no problems at all. This season im experimenting a bit and using the suit to relieve squeeze and on the incredibly rare occasion i need a bit more, using the BC to add that. When starting my ascent i empty all air from my BC and transfer to using suit-only for buoyancy as theres less scope for error handling one air source. When i get to deco stop depth i want no air in my BC and be neutral via my suit. The reason for this is air in the suit keeps me warmer during my stop.

Both methods have pros/cons and obviously diving heavy such as twinsets means you have to use a BC to compensate but correctly weighted on singles you should be near enough neutral with squeeze removed and absolutely fine to control buoyancy with suit alone.

 

[scubadobadoo]

I agree with String.

 

[mempilot]

It is much easier to control bouyancy within the confined space of a bc bladder than spreading it out across your whole body. I agree, that at shallow depths, enough air in the drysuit to eliminate squeeze should be enough to remain neutral when weighted properly. But diving is dynamic, and stability is crucial. A bc is designed to keep the center of bouyancy static and in the right place to conteract the equipment weight we wear. No drysuit manufacturer designs a suit to hold air in the proper places. If a dry diver needs to position underwater any other way than horizontal, then any amount of air becomes dynamic. This excess air is free to flow to the wrong places.

To the original poster. There are many ways to do this. But only one way that it was designed to work. Ask why there isn't an oral inflator or butt dump on a drysuit and you'll start to get the picture.

 

[gj62]

To the original poster. There are many ways to do this. But only one way that it was designed to work. Ask why there isn't an oral inflator or butt dump on a drysuit and you'll start to get the picture.

Drat - about 6 months ago I could have sent you a picture of a drysuit with an oral inflator - you know, they had drysuits before auto-inflators, so oral was what you used... :11: As far as the butt dump, it got uncomfortable when I was sitting around between dives so I moved to my shoulder...

 

[mempilot]

Drat - about 6 months ago I could have sent you a picture of a drysuit with an oral inflator - you know, they had drysuits before auto-inflators, so oral was what you used... :11: As far as the butt dump, it got uncomfortable when I was sitting around between dives so I moved to my shoulder...

Could use that butt dump every once in a while depending on the previous night's cuisine!