steel buoyancy

TMHeimer · Oct 9, 2009

Both my steel 120 and 71.2 tanks are negatively buoyant. I have 24 lbs. (salt water) in the BC. When I'm totally inflated it will sink. This means I can't do the unit removal/replacement skill at the surface. Anyone else have this problem?

JahJahwarrior · Oct 9, 2009

Why do you have that much weight in the BC? Have you considered moving any of that weight to a weight belt for the purpose of the drills, if not for all of your diving?

SCUBA482 · Oct 9, 2009

I agree...I've dropped 14 lbs when I switched to my stell HP100's from the Al80...perfect bouancy now..

Notso_Ken · Oct 9, 2009

TMHeimer:
Both my steel 120 and 71.2 tanks are negatively buoyant. I have 24 lbs. (salt water) in the BC. When I'm totally inflated it will sink. This means I can't do the unit removal/replacement skill at the surface. Anyone else have this problem?

I think you need to do a good weight check on your next dive. I think you may be overweighted, with negative tanks and 24lbs.

Just in case you aren't familiar, at the end of the dive, when you've got your tank down to 500psi (or metric equivalent), dump all the air from your BC, and see if you are neutrally bouyant (absent any force acting on you, you stay in place and don't sink or rise). Then, when you surface, again, make sure your BC is empty, exhale fully, then see how you float. You should be at the surface apprximately eye level, or a little less. You should not go screaming to the bottom.

Good luck!

Ken

PS, I keep 10lbs on a belt, then finetune the lead in the BC for which suit I'm wearing, what type tank, and whether fresh or salt water. Typically, I have a total of 22 lbs with a positive bouyant tank in fresh. 22lbs with a negative tank in salt.

Diver0001 · Oct 9, 2009

TMHeimer:
Both my steel 120 and 71.2 tanks are negatively buoyant. I have 24 lbs. (salt water) in the BC. When I'm totally inflated it will sink. This means I can't do the unit removal/replacement skill at the surface. Anyone else have this problem?

Tell us about your suit.

R..

TMHeimer · Oct 9, 2009

A few years ago my Instructor in the PPB course figured I was overweight, but he was surprised to find that I wasn't--I need 34 lbs. in salt water with the steels, 40 with an AL80. We found that with 10 in each BC pocket, 2s in the shoulder pockets and 10 on the belt my trim is as good as possible. I haven't had any buoyancy problems my last 100 dives or so, and can hover effortlessly. Needless to say I have no problems with the unit removal/replacement drill at the surface when doing it in the pool with only a weight belt. I guess if I moved some weight from the BC to the belt when in the unit could become positively buoyant, but that may screw up my trim.

waynne fowler · Oct 9, 2009

yeah that's what you needed then TMH but when is the last time you did a proper weight check?
perhaps tells us your height, weight (are you lean or....?????) what suit do you where, undergarments? what type of bcd.

TMHeimer · Oct 9, 2009

Waynne, Must admit I haven't done one since that course 2 years ago. I'm 55, 6 feet, a little under 200 lbs. I USED to be lean.... I wear 7 mil farmer john, hood, 5 finger gloves. Genesis BCD.

waynne fowler · Oct 9, 2009

LOL@ USED to be

@ 6' and under 200 I'd say your certainly not chubby!

I don't imagine your really all that far off TMH but there's no question my friend, it's time for another weight check... and don't go too long (20 dives or so) between checks. Our bodies, equipment and various other things are always changing and a good weight check doesnt take much time at all. Notso Ken in post #4 gave a good discription of the weight check. However while not a bad thing I don't think the surface check really does much good for someone whos getting close to the right weight... but then again... I've been wrong before =^)

drdaddy · Oct 9, 2009

TMHeimer:
Waynne, Must admit I haven't done one since that course 2 years ago. I'm 55, 6 feet, a little under 200 lbs. I USED to be lean.... I wear 7 mil farmer john, hood, 5 finger gloves. Genesis BCD.

I'm 5'10", 200 lbs, use a 7mil farmer john, and use 20 releasable lbs in my BCD and 6 lbs on a weight belt in salt water. BCD is an AquaLung/SeaQuest Pro-QD with a steel 100 cuft HP 3442 tank.

I have found that different make farmer john wetsuits really vary in their buoyancy. And older ones are less buoyant than newer ones.

steel buoyancy

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