Wet Suit Buoyancy Effects

I searched the forums but didn't see this specific question having been asked among the many posts on buoyancy. I just finished taking an OW certification course as a refresher, having been certified back in 1973 but not having dove for many years. During the course, in a pool with deflated BCD and no wetsuit, I found I needed 4 lbs of weight to be neutrally buoyant (using aluminum 80 single tank). Doing some quick buoyancy calculations I would expect to need to add 1 more lb weight (5 lbs total) if I'm rigged the same way on a seawater dive. I am 6' tall and weigh in at 202 lbs.

My question is this: how much additional weight did you need to add for your wet suit? I realize this is a broad question, with different sizes of folks, different thicknesses of wet suits, full vs. shorty, etc., but what I'd like to try to understand is a reasonable expectation for additional weight needed specifically for a neoprene wet suit when I hit the ocean. Any thoughts and help from your experience will be much appreciated.

BarryTX:

During the course, in a pool with deflated BCD and no wetsuit, I found I needed 4 lbs of weight to be neutrally buoyant (using aluminum 80 single tank). Doing some quick buoyancy calculations I would expect to need to add 1 more lb weight (5 lbs total) if I'm rigged the same way on a seawater dive. I am 6' tall and weigh in at 202 lbs.

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1 lb sounds a bit low. Sea water is roughly 2% more dense than fresh water. If you weight 202 lbs, assuming roughly 50 lbs of equipment, you would have to ADD roughly 5 lbs, giving you a total of 9 lbs.

Just adding a 5 ml flanged hood and some gloves to my usual 5 ml full suit makes me add more than a pound. (from starting lead of 7 lb)

Putting on a 5 ml vest with hood and gloves causes my buddy to add about 3 lbs to his previous wt, and he's a big guy.

Just some data points for reference...

BarryTX:

My question is this: how much additional weight did you need to add for your wet suit? I realize this is a broad question, with different sizes of folks, different thicknesses of wet suits, full vs. shorty, etc., but what I'd like to try to understand is a reasonable expectation for additional weight needed specifically for a neoprene wet suit when I hit the ocean. Any thoughts and help from your experience will be much appreciated.

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Roll up the wetsuit you want and toss in a pool. Keep adding weights until it sinks.

WAG: For your size, a 5mm full suit, hood and gloves start with an added 10lbs. Less for a 3mm, more for a 7mm suit - then do a real buoyancy test.

I found this linked on another site:

Here's another thread on the topic with general guidelines from the PADI Bouyancy text.

http://www.scubaboard.com/forums/basic-scuba-discussions/271513-weights-no-suit.html

Most students I've worked with required about additional 5lbs going from pool to ocean in the same identical configuration. As has been pointed out, each item of neoprene added or subtracted changes the equation as does the thickness of those items. The guidelines will give you a ballpark starting weight, but the rest is trial and error doing bouyancy checks before and after your dives to ensure you are sufficiently weighted to safely complete your safety stops at 15ft with a near empty cylinder. After that, with time and practice, as your bouyancy skills improve and you relax in the water, you will slowly be able to reduce your weighting in small increments.

Great info, thanks much for all the quick feedback. Looking back at my quick and dirty calculations, sure enough it was 5 additional pounds, not 5 total. I probably underestimated the equipment weight so the chart showing 7 lbs is sounding pretty close. The comments on wet suits and the chart above will help me to make my first guesstimate. If at all possible, I will test in a pool first - my whole desire is to avoid needing to reboard a boat to get more or drop off weight. Thanks again to all, this is very helpful.

IMHO- If I were doing a boat dive and was not sure of my weight. Guess heavy and try to put some small weights in your pockets 1-2's. At the end of your 1st dive and after a successful safety stop with a near empty tank. Then do a buoyancy test at the back of the boat removing the small weights until your good. Keith