Wing lift - the X factor

[Gombessa]

Perhaps there is an approximate formula that is relative to the dry weight of a wet suit. For instance lets say a wetsuit weighs 4lbs dry and it has 12lbs of positive buoyancy. Then suits made with the same material should have approximately the same dry weight to buoyancy constant. A suit made of the same material except thicker than the above example perhaps say 6lbs dry would have a positive buoyancy of 18lbs.

Couv, I have no idea if that is the case, but I imagine most people have a bathroom or postal scale, and if that does turn out to allow one to be able to ballpark a buoyancy figure in their home, I'm all for it. It would be great if that gets us closer than the rules-of-thumb we otherwise rely on.

 

[cool_hardware52]

Couv, I have no idea if that is the case, but I imagine most people have a bathroom or postal scale, and if that does turn out to allow one to be able to ballpark a buoyancy figure in their home, I'm all for it. It would be great if that gets us closer than the rules-of-thumb we otherwise rely on.

Probably not going to work.

Neo varies quite a bit, and the buoyancy is not linear with respect to thickness.

By this I mean "6mm" neo won't have twice the buoyancy of "3mm", it will more than twice the buoyancy.

Why? Because neoprene has few voids near the surface or skin.

Proportionally thinner neo has more of it's thickness as "skin" and less as compressible foamed "core"

For a given material and thickess buoyancy per unit weight should work ok, but not across different materials and or thickness.

Tobin

 

[RonFrank]

The fact is that a suit is only ONE variable in many that determine buoyancy requirements. Take it a step farther, what are the buoyancy characteristics of a BC, gloves, hood, first stage, tank, and the individual?

The solution to the buoyancy question is quite simple, and covered in OW class. That said, most divers when new require more weight than they should for many reasons.

Weighting can be a bit of a challenge, but if in doubt, dive over-weighted!

As for wing lift, the average diver needs somewhere between 18~35lbs. Just because you need 30lbs of lead does not mean 30lbs of lift will not be enough to keep you buoyant on the surface. Keep in mind weight allows one to sink, but the reason it becomes necessary is not tied directly to the lift required. IOW's you are buoyant, your suit is buoyant, as is the tank (AL80) when low etc.

 

[jtpwils]

Well, even if manufacturers don't publish it, some people do test it and publish the results.

From another thread I wrote titled Bare Velocity 3/2 => No extra lead

I just bought a Bare Velocity 3/2 Progressive stretch full suit.

According to the ScubaDiving test results they say it has zero inherent buoyancy.

Will I actually need no additional lead when wearing this suit as compared to being in no suit at all?:shocked2:

If the test results of "no inherent buoyancy" at the surface are accurate, and surely the suit has buoyancy, but it's equal to it's weight, look at what happens when I
When I descend the suit compresses and I am now less buoyant than I was if I wasn't wearing any suit at all. Seemingly opposite to what one would expect with a suit on, but yet absolutely what really happens if the test is accurate.

So while wearing the suit I would have no change in ballast required at the surface but would need less weight at depth and have a different "rate of change" in buoyancy with depth than I had before.

Note: A few folks posted in that thread that they have found that they need no additional weight when wearing the above suit.

 

[cool_hardware52]

Well, even if manufacturers don't publish it, some people do test it and publish the results.

From another thread I wrote titled Bare Velocity 3/2 => No extra lead


If the test results of "no inherent buoyancy" at the surface are accurate, and surely the suit has buoyancy, but it's equal to it's weight, look at what happens when I
When I descend the suit compresses and I am now less buoyant than I was if I wasn't wearing any suit at all. Seemingly opposite to what one would expect with a suit on, but yet absolutely what really happens if the test is accurate.

So while wearing the suit I would have no change in ballast required at the surface but would need less weight at depth and have a different "rate of change" in buoyancy with depth than I had before.

Note: A few folks posted in that thread that they have found that they need no additional weight when wearing the above suit.

Just how buoyant to you expect a 3/2 to be?

Tobin

 

[jtpwils]

LOL - that's the original question isn't it?

Seriously though - being brand new to diving I had no idea and so I wondered what it might be and looked it up. I didn't search to find out what a 5 or 7 mil suit would be but maybe that data is outhere also.

 

[cool_hardware52]

LOL - that's the original question isn't it?

Seriously though - being brand new to diving I had no idea and so I wondered what it might be and looked it up. I didn't search to find out what a 5 or 7 mil suit would be but maybe that data is outhere also.

IME a typical one piece full 3mm suit on a diver of average stature is 4 lbs or less positive.

A "3/2" would be even less.

2-3 lbs may well be below the resolution of your "experiment"

Tobin

 

[jtpwils]

Thanks Tobin. The point of my post (in this thread - not the other) wasn't to try and figure out the weight requirement of that suit but to point out that there may be test results out there that give the info the OP was looking for.
Alas, so far my own searching didn't turn up much for anything other than the thin suits posted above.