Negative Bouyancy achieved

[Hillmorton Scubie]

Sorry for asking a question that I'm sure has been asked before.
In warm sea water-What depth will I start to become negative. (No wet suit/No weight belt)

 

[JeffG]

Depends on your starting point (buoyancy ) and your lung capacity.

 

[holdingmybreath]

I don't think there is any way to figure this out without going out and seeing for yourself. A muscular build, small lung capacity.. and your negative at the surface.. A soft build and you're buoyant at the surface, and you can see that just where a person becomes negative could really vary. I've seen a very solid football player/weight lifter sink with a small life vest on (fresh water)

 

[rakkis]

Just to make sure the OP is clear on this.... without a wetsuit to compress as you descend, your buoyancy doesn't change as you descend.

Water is the same density within recreational depths/pressures. You don't become more negative just because you are deeper.

(Assuming you maintain your bcd at the same volume throughout)

 

[Walter]

Just to make sure the OP is clear on this.... without a wetsuit to compress as you descend, your buoyancy doesn't change as you descend.

Of course it does. We're not talking about SCUBA, so there's no compressed air to keep the lungs at their surface volume. As you descend, your lungs compress making you less buoyant. Jeff nailed it. Some may be negative at the surface, others will become negative as they descend while others will remain positive at any depth.

 

[freediver]

Of course it does. We're not talking about SCUBA, so there's no compressed air to keep the lungs at their surface volume. As you descend, your lungs compress making you less buoyant. Jeff nailed it. Some may be negative at the surface, others will become negative as they descend while others will remain positive at any depth.

Yes, in fact, with practice a freediver can shift their air toward the upper or lower part of the lung in order to make themselves a bit more buoyancy specific.

 

[BDAfreediver]

I'm one of those people who are overly buoyant and tend to float no matter what and negative buoyancy is very hard to achieve personally. I actually have to have weights to get down easily and with a wetsuit and some soft weights. It really does depend on your body your lung capacity and how practise you are at free diving to find your own negative buoyancy... anyways I'm repeating I'm sure but good luck!

 

[rakkis]

Snorkeling/Freediving forum?! Damn it.. I knew I should have taken a *right* at Albuquerque.:anonymous:

 

[Hillmorton Scubie]

If you watch this video clip, you will see that this guy is definitely negative as he sinks without swimming, and then has to make considerable effort to reach the surface.

YouTube - William Trubridge freedives THE ARCH at Blue Hole, Dahab