Body Fat & Bouyancy?

[mohave_steve]

I just got back in the water after an extended dry spell. Before diving I checked my log book to double check how much weight I had been carrying while diving the specific gear I would be using on this dive. 7mil full suit & AL80 etc. 16lbs looked right.

I made the first dive with 16lbs and was OK until the end of the dive. I was too light to hold my safety stop without finning down. I added 2lbs for the second dive. Still not enough.

Same gear I have been diving for 5+ years. Only change I can identify is that my wetsuit appears to have shrunk a bit in the midsection

I am 10-12lbs heavier than I was on my earlier dives. Is fat that bouyant as to account for me needing 3 or more pounds of additional weight?

 

[fnfalman]

Yes, the fatter the person, the more weight that person needs to carry to compensate for the fat.

If I were to lose about 20-lbs of body weight, I can probably lose about 5-lbs worth of lead.

 

[idocsteve]

Yup.

Get your butt on that treadmill.

There are other problems that may result from that extra 10-12 lbs.

 

[redacted]

Body fat has a density of .9 g/cm^3 so a weight gain of 10 to 12 pounds would be offset by less than 2 additional pounds of lead. So, some of your problem may be technique/comfort or you may also have traded some muscle (1.06 g/cm^3) for fat.

 

[Nemrod]

I just got back in the water after an extended dry spell. Before diving I checked my log book to double check how much weight I had been carrying while diving the specific gear I would be using on this dive. 7mil full suit & AL80 etc. 16lbs looked right.

I made the first dive with 16lbs and was OK until the end of the dive. I was too light to hold my safety stop without finning down. I added 2lbs for the second dive. Still not enough.

Same gear I have been diving for 5+ years. Only change I can identify is that my wetsuit appears to have shrunk a bit in the midsection

I am 10-12lbs heavier than I was on my earlier dives. Is fat that bouyant as to account for me needing 3 or more pounds of additional weight?

Yes, fat is less dense than muscle and bone and yet as a result of it's accumulation you displace more water and are thus more buoyant as a result.

N

 

[1_T_Submariner]

Where you using hard weights?
I just got back from a trip where they gave us soft weights and I thought it was funny that a pair of 5's weighed less than a pair of 4's they where homemade weight pouches so I really didn't worry about it that it seem to take more to weigh me down than normal.

Diving is a great motivator to excercise! I don't dive to excercise I excercise to dive.

 

[Buoyant1]

Where you using hard weights?
I just got back from a trip where they gave us soft weights and I thought it was funny that a pair of 5's weighed less than a pair of 4's they where homemade weight pouches so I really didn't worry about it that it seem to take more to weigh me down than normal.

Diving is a great motivator to excercise! I don't dive to excercise I excercise to dive.

That! IF it weren't for diving, I'd skip the gym!

 

[TyGuy]

muscle sinks fat floats...im about the same weight as a dive buddy, but im more muscle hes more mush. i use alittle more than 5 lbs of weight less

 

[lulubelle]

Sometimes it is hard to make sense of weight requirements. Certainly my requirements have gone down as I have gained experience. It will be interesting to see what my requirements are this summer. Although my body weight hasn't really changed, I have lost a LOT of muscle.

 

[paddler3d]

It has been a while since you've been in the water. You could be doing a bit of what new divers do and don't relax. They don't hold their breath, but they don't seem to exhale deeply and need more lead! I've done the 10+# add on and my lead hasn't changed that much.