Buoyancy in salt water vs fresh

[karlimmergut]

Here's how I would calculate it. The density of human body is similar to that of salt water, so assume 64 lbs/cuft. I weigh 200lbs, so my body volume is about 200/64=3.125 cuft. More in a wetsuit, mask and fins, so perhaps round up to 3.2. The AL80 cylinder holds 80 cuft at 3000psi, which is about 200x the atmospheric pressure, so the volume of the air in it is about 80/200=0.4 cuft. Since the walls of the cylinder, valves, and the BC also add some volume, throw in another 0.4 cuft for that. In total, 4.0 cuft for a 200lbs diver in full equipment. The difference is water density is 64-62.4=1.6 lbs/cuft, that comes out to 4.0*1.6=6.4lbs in total, which is consistent with what someone else here recommended earlier.

 

[Max Speed]

You're welcome to spend some time at the tables with me in Vegas.

Sent from my SPH-P100 using Tapatalk 2