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Tips to Calculate Your Scuba Weight
You Have to Get Wet
It's no one item that determines your buoyancy, but you plus all your gear together.
You can "ballpark" guess how much weight you need with experience, but you can only fine tune it by getting in the water.
Pay Attention to Your Tank
Cylinder buoyancy characteristics change your buoyancy a lot. So, recheck your weight when changing to a different size and/or different material (steel vs aluminum) tank. Usually, but not always, going from aluminum to steel requires removing weight.
Air is Air
A common misconception is that with X cylinder, you don't need to worry about weight change due to air consumption. This is not true. Once you're properly weighted, consuming 70 cubic feet of air reduces your weight exactly the same whether it you breathed it from a steel or aluminum cylinder.
Build Muscle to Drop Weights
Muscle is denser than fat, so the more you build, the less weight you need to submerge.
Recheck
Any change to your kit affects your buoyancy. This is obvious with a big change ,like going from a wetsuit to a drysuit, but lots of little changes like a new knife, different computer and upgrading your regulator can add up
Check at Your Safety Stop
With 500 psi at 15 feet, if you vent all the air from your BCD, you should be very close to neutrally buoyant, rising slowly as you inhale, sink slowly as you exhale. If not, adjust your weight afterward -- but if you've followed the other steps, you should be very close and fine adjustments should do it.
Log It
Although you might find a scuba diving weight calculator or buoyancy calculator online, in the end they're only going to get you close and you'll still have to get wet to dial it in. A much more useful way is to write down what exposure suit you wore, what equipment you used, how much lead you carried, how much your body weighs, how much weight you needed etc., after each dive. This gives you a good start point for checking your weight each time, and over time you'll have the start point you want for different exposure suits, salt or fresh, aluminum or steel tank and so on.
Keep it up until you get your weighting correct. With experience, you'll discover that the best scuba weight calculator is your log book and brain followed by a buoyancy check. Even if you've got a new BCD or wetsuit, you'll be able to estimate the lead you need within a couple of pounds. You'll be your own dive weight calculator.
Breath Control
If your weighting is correct, at a given depth you can control your buoyancy with your lungs alone most of the time (unless you're using a rebreather). With practice, you'll do this without thinking instead of grabbing your low-pressure inflator hose every time you need to make a minor adjust
Be Patient.
Water is a viscous fluid, more like molasses than air, so buoyancy changes can seem slow or delayed if you're new to diving. When you want to ascend a little, you inhale and it takes a few beats before you start to rise. This is why many divers don't realize how well they can control their buoyancy with breathing. Give it a minute as you breathe in and out (slowly and deeply) to see what adjustment you can achieve naturally.
For the remainder of this article Use the link below.
Buoyancy Calculator—How Much You Need in Dive Weights | Scuba Diving
