Buoyancy

[hambone79]

I'm currently working on getting my NAUI Scuba Diver certification and I had my first session in the swimming pool on Wednesday. Everything went great...I had no problem finding a lost regulator, clearing a flooded mask, taking off/putting on a mask underwater, or sharing air with a buddy. The only thing I found odd about the whole session is that I did not need a weight belt. My instructor put me in the water with all my gear on and had me take a deep breath while I was in a vertical position and being very still. Even with my lungs completely full of air, I slowly sank to the bottom.

The instructor told me that being negatively buoyant isn't very common, so I was just wondering if anyone else on this board is negatively buoyant?

 

[mccabejc]

Your gear didn't include a wetsuit, did it? If so, then man, you're made out of metal or something. :11:

 

[eponym]

The instructor told me that being negatively buoyant isn't very common, so I was just wondering if anyone else on this board is negatively buoyant?

I am. I do warm-water ocean dives with a 3-mil shortie and no weight other than the steel 80 on my back.

As it turns out, not every skinny guy is negative. And I know one or two "rounder" types who are quite dense (physically). The relative densities of fat and muscle are actually rather close to each other, so there may be other factors at play, such as bone density or lung capacity or other air spaces (like in my head).

-Bryan

 

[hambone79]

Your gear didn't include a wetsuit, did it? If so, then man, you're made out of metal or something. :11:

Since we were in an indoor pool a wetsuit wasn't necessary. My instructor said that even with a shorty I probably wouldn't need any weight or only a small amount of weight.

I am 6' tall a weigh about 175 lbs....I have some body fat around my mid section and I figured that would make me some what buoyant, but I guess I was wrong.

 

[mempilot]

You're less buoyant in fresh than salt. I only need about 2lbs without neoprene in the pool. In the big pool, I need 4lbs. With a wetsuit, it goes up 4lbs for either.

And for the steel 80: that might have something to do about it.

 

[Gary D.]

I'm negatively buoyant and have been all my life. Nothing the matter with it.

The Navy said it was 1 in 110K people but who knows for sure. That sure seems like a low percentage.

Gary D.

 

[MB]

The Navy said it was 1 in 110K people

1 in 110,000??? No Gary, you're at least 1 in a million!

 

[jbd]

I'm currently working on getting my NAUI Scuba Diver certification and I had my first session in the swimming pool on Wednesday. Everything went great...I had no problem finding a lost regulator, clearing a flooded mask, taking off/putting on a mask underwater, or sharing air with a buddy. The only thing I found odd about the whole session is that I did not need a weight belt. My instructor put me in the water with all my gear on and had me take a deep breath while I was in a vertical position and being very still. Even with my lungs completely full of air, I slowly sank to the bottom.

The instructor told me that being negatively buoyant isn't very common, so I was just wondering if anyone else on this board is negatively buoyant?

What gear were you using i.e. steel or aluminum tank, standard type of BC or BP/wings? If BP/wings was the plate steel or aluminum?

Besides all this, maybe your just another lucky one in 110K

 

[hambone79]

What gear were you using i.e. steel or aluminum tank, standard type of BC or BP/wings? If BP/wings was the plate steel or aluminum?

Besides all this, maybe your just another lucky one in 110K

To answer your question...I was using an aluminum tank and jacket style BC.

 

[Battery]

1 in 110,000??? No Gary, you're at least 1 in a million!

Well, according to this Forum, it's 2 in 29,490