Getting Your Weighting Right For Proper Buoyancy

[diver0008]

I read once, that with proper weighting, at the surface, BC fully deflated, you should be eye-level with the water's surface with lungs full. Exhale and down you go.

This procedure worked well for me.

Curious to know if it sounds right to others, and any other techniques useful for new divers.

 

[tursiops]

Was your tank full or empty? That makes a difference of 5-6 pounds, depending on the tank.

 

[Diamond Reef]

The trick is, we're you able to hover between 15-20' for three minutes when your cylinder got down to 2-300psi without holding on to a downline?

 

[divin'dog]

It's a pretty good place to start... For me, I was at eye level with a normal exhale. There was only about 100-200psi in my tank.

 

[TMHeimer]

Splitting hairs, but it's holding a "normal" breath. Lungs full could be a gigantic breath....

 

[herman]

Not really splitting hairs, that extra half breath can be an extra 2 or 3 lbs. depending on your physical size.

You are close, with an empty tank, no air in the BC and a half breath. Or with a full tank, once you find the correct weight add an additional amount of weight to compensate for the gas you will use from the tank (about 4lbs for an 80).

Some additional tips:

Make SURE you are not finning. I have seen students kicking away and swear they weren't. This will greatly impact the amount of weight you "think" you need.

When you exhale fully and hold it, you should stay at the surface for a few seconds then SLOWLY start to descend. Your decent should begin very slow and increase as you descend, both from wetsuit/air pocket compression and inertia. If you immediately start to sink or do so rapidly, you are overweighed. Many people think the decent should start instantly and go fast, that is incorrect and if you do, you are a good bit overweighed.

 

[Neilwood]

Not really splitting hairs, that extra half breath can be an extra 2 or 3 lbs. depending on your physical size.

You are close, with an empty tank, no air in the BC and a half breath. Or with a full tank, once you find the correct weight add an additional amount of weight to compensate for the gas you will use from the tank (about 4lbs for an 80).

Some additional tips:

Make SURE you are not finning. I have seen students kicking away and swear they weren't. This will greatly impact the amount of weight you "think" you need.

When you exhale fully and hold it, you should stay at the surface for a few seconds then SLOWLY start to descend. Your decent should begin very slow and increase as you descend, both from wetsuit/air pocket compression and inertia. If you immediately start to sink or do so rapidly, you are overweighed. Many people think the decent should start instantly and go fast, that is incorrect and if you do, you are a good bit overweighed.

Good way to prevent that is make sure the feet are crossed - near impossible to fin that way (dolphin type kick would almost be possible but difficult).

 

[tbone1004]

here's how i like to do it. Intentionally overweight yourself by 5-10lbs, and have a buddy on the surface with a luggage scale weigh you. Doesn't matter if the tank is full, empty, or somewhere inbetween, just that you are overweighted, and he has a reasonably accurate luggage scale that is attached to you. Cross your ankles, flood the suit, dump all the air from the bc, and just hang out with your head about a foot below the surface. Buddy should note how much the scale is reading, and that is how overweighted you are. Add back in the weight of the air in your tank, 0.08lbs/cf and you'll be as close as you could ever hope to be. MUCH faster than trial and error weight checks, and much more accurate

 

[Neilwood]

here's how i like to do it. Intentionally overweight yourself by 5-10lbs, and have a buddy on the surface with a luggage scale weigh you. Doesn't matter if the tank is full, empty, or somewhere inbetween, just that you are overweighted, and he has a reasonably accurate luggage scale that is attached to you. Cross your ankles, flood the suit, dump all the air from the bc, and just hang out with your head about a foot below the surface. Buddy should note how much the scale is reading, and that is how overweighted you are. Add back in the weight of the air in your tank, 0.08lbs/cf and you'll be as close as you could ever hope to be. MUCH faster than trial and error weight checks, and much more accurate

Do you have this factor in metric for those of us over the pond who use kg & litres? I am needing to get my weighting (entire set of new kit since my last dive) and looking for the quickest way to get my weighting right.

 

[tbone1004]

1.286g/l