Variation in buoyancy - Different types of wetsuits

[bolts]

Hi all,

Poked around the forum a bit, and didn't quite find what I was looking for. I'm wondering if anyone has any information or experience with how much lead you can take off or put on to maintain similar buoyancy characteristics for different wetsuit configurations, all other things being equal.

My specific query is the difference between using a 7mm john/jacket combo and then going to a 7mm fullsuit. I'm expecting to be less buoyant in the fullsuit due to less neoprene, but does anyone know if I'll need to change up my weight setup drastically? With the john/jacket I dove with about 26lbs, and the suit itself was fairly large (XL, I'm 6'4" and about 205lbs).

 

[Hawkwood]

The only true way is to figure it out is do a proper weight check. One could not do other than to "guess".

Had the two-piece suit "lost" some of it's buoyant characteristics due to age? Just one of the variables to consider.

 

[bolts]

Of course you're right, the check is the only real way. I'm doing a dive in the new suit tonight, so I'm just curious as to what to expect, that's all.

The john/jacket suit is an ex-rental, so it has loads of dives on it.

 

[redacted]

There is another way that avoids problems during dives. All of my wetsuits and major neoprene components get "weight" in a pool before I put them on for a dive. I use a mesh bag and an array of lead weight to measure and log their buoyancy. Knowing my buoyancy sans exposure protection, I can easily and accurately adjust for different tanks, salt vs fresh water, and exposure protection. When it might be close I just go with the extra pound and do a weight check at the end of my first dive.

 

[Hawkwood]

In that case, you may find no difference? Maybe just a few (couple) of pounds either way?

No clear cut answer - how's that for wiggling out of providing an answer?

Best advice would be to make sure that with the weights you are bringing with you also include some small increments (1 and 2 lbs). Nothing worse than deciding you are a couple of pounds heavy only to discover you only have 5 lb weights.

Bill

 

[Crush]

Personally I'd drop four pounds from my gear but keep it readily accessible (on shore, or even in the water) in case you have to add it.

If you have both suits and own your own weight you can place the suits in a bathtub full of water (careful not to trap air bubbles) under an aluminum cookie sheet and see how much weight you have to pile on the cookie sheet to sink each suit. The difference in the weights is an approximate measure of the difference of the buoyancy of suits - the buoyancy difference will change somewhat when stretched over your body, but not too much.

 

[bolts]

I tried the dive with 2lbs less than I normally do, just to be cautious (I'd much rather been a bit heavy than a bit light), and I found myself a little heavy on the bottom. I'll try for 4lbs less next time. Thanks for the advice!

I will say this, a good fitting suit REALLY does keep you warm. Wow. Not that my old suit was a horrible fit, but I was impressed with this new suit.