How to correct if you're overweighted?

[guymenton]

I'm newly NAUI O/W certified, and for weighting, I've been using the 10% bodyweight + 10 formula we were taught. But this is probably an overestimate. I'm thin (5'7", 130lbs) and diving with 24lbs with a 7mm suit. How do I find out how much extra weight I can shed?

At the end of a dive with 500psi left, and no air in my BC, I should be neutrally buoyant at 15fsw right? So, at the end of the next dive, should I dump all my BC air, and start handing weights over to my buddy until I start hovering off the bottom?

 

[Fly N Dive]

i belive that you have the right idea, but i was told that with little or no air in your tank, at the surface with no air in your bc and a lungfull of air you should float at eye leval, and when you exhale you should be negative

 

[jbd]

I'm newly NAUI O/W certified, and for weighting, I've been using the 10% bodyweight + 10 formula we were taught. But this is probably an overestimate. I'm thin (5'7", 130lbs) and diving with 24lbs with a 7mm suit. How do I find out how much extra weight I can shed?

At the end of a dive with 500psi left, and no air in my BC, I should be neutrally buoyant at 15fsw right? So, at the end of the next dive, should I dump all my BC air, and start handing weights over to my buddy until I start hovering off the bottom?

That would be one method. There are several others that have been posted on scubaboard. Instead of using the bodyweight formula, I teach my students to to use a weight belt with evenly spaced weights on it. Put all your gear on, lay the belt on the bottom of the pool or some similar place where the water is 5 or 6 feet deep. While in the water make sure all the air is out of your BC. Take a slightly larger than normal breath, hold it and dive down to the weight belt. You do not have the regulator in your mouth. Grab a hold of one end of the weight belt and hold it close to your navel and totally relax and completely limp. You will float toward the surface until the proper amount of weight has been lifted off the bottom. Count that up and you now know how much weight you need based on the laws of physics in regards to bouyancy.

I know people who are your size and using the same exposure protection and gear they use only 12 to 14 lbs. I think that the formula you were taught leaves most people overweighted.

 

[fmw625]

I dive with 4# with al80 and and a .5mm dive skinand have no problem. I'm 5'7" 160 lbs., but I am negative bouyancy natrually.

 

[waterwraith]

Head to a pool with a tank that contains about 500psi and put all the lead in your BC pockets then go down to 10 ft with no air in your BC. Make sure your wearing all of the gear you use including your wetsuit. Once you are at 10 ft start taking the lead out until you are neutral. It sounds like you are probably at least eight pounds heavy.

 

[Ontario Diver]

Weight is a changable issue - especially for a new diver. As you get more and more comfortable underwater, you will need less and less weight. Your "perfect" weight will change often.

Relax and have fun. If you are a little overweight, you just need to add air to the BC but being under weighted is a right pain in the a$$. Err on the side of being heavy at the start.

Dive and play.. The right weight will come without mathematical calculations.

 

[Walter]

At the end of a dive with 500psi left, and no air in my BC, I should be neutrally buoyant at 15fsw right?

No. You should be neutrally buoyant with full lungs at the surface. If you weight yourself at 15 feet, you'll pop to the surface from your safety stop.

I've been using the 10% bodyweight + 10 formula we were taught.

That's a new one. They used to incorrectly teach 10% of body weight and that was still normally way too much for most people. There is such a wide variety of body types/gear configurations that no such formula is ever accurate.

 

[Charlie99]

. How do I find out how much extra weight I can shed?

So, at the end of the next dive, should I dump all my BC air, and start handing weights over to my buddy until I start hovering off the bottom?

Another method is to simply take off a pound or two after each dive until you get down to the right point.

 

[guymenton]

Thanks everyone for your input. This is very educational. One more question....does the type of tank (steel or alum) and size have anything to do with it too?

From what I've read so far, one simple, quick way to know if I'm overweighted, is at the end of my dive, with very little air left in my tank, I'll deflate my BC at surface and take a deep breath. If I continue to float around eye/face level, I'm in the right ballpark, if I sink, then I have too much weight on -- sound reasonable?

 

[northcoast_diver]

Head to a pool with a tank that contains about 500psi and put all the lead in your BC pockets then go down to 10 ft with no air in your BC. Make sure your wearing all of the gear you use including your wetsuit. Once you are at 10 ft start taking the lead out until you are neutral. It sounds like you are probably at least eight pounds heavy.

If you cannot do this, then the next best thing is to head to a pool with all of your wetsuit gear, including boots, gloves, and hood, and set your weights by the side of the pool.

Add weight to your weight belt until you are neutrally buoyant at the surface. That happens when you start to sink upon exhaling, and float at eye level when inhaling through your snorkel.

For the ocean you would then add another 6 lbs.

Ultimately, what you originally said it true. You need to test your buoyancy at the ocean, at the end of a dive, at 15 ft, with your B/C fully deflated. If there is any air in the B/C, then you are overweighted. If overweighted, then you need to subtract 2 lbs at a time, per dive, until you get the weighting right.

Your proper weighting is not fixed in stone. With different suits, it will be different. From season to season, year to year, it can be different as well, if you have gained or lost weight during the off season.

You would also need more weight with an aluminum tank, since these tend to become positively/buoyant as they empty.