Calculate your weighting

Conduct a Proper Weight Check - It's Worth It!

Being properly weighted makes all the difference in how easily you can control your ascents and descents. Proper weighting reduces your risk of runaway ascents and descents, improves your air consumption, and can make proper horizontal trim easier to establish.

The only way to know exactly how much weight you need is to go for a dive in all your gear and figure it out by performing a weight check. 

1. With a fully deflated BC at the surface, add or remove weight until you can float at about eye level while holding a full (but not huge) breath.  If you're using a drysuit, it should be inflated enough to remove suit squeeze - but without any excess gas. 

2. With your regulator in, exhale to sink. You should sink slowly, if not, you are overweighted.  

3. Inhale (but do NOT hold your breath!) to float back to the surface.  

4. You should float neutrally in the water column, neither rising nor sinking, when you are mid-breath. This is the essence of neutral buoyancy for open circuit diving. 

If you have done this exercise with a mostly empty (just above 500 PSI) tank - then you're done! This is the proper amount of weight for the equipment you are wearing. You should have just enough to be able to stay underwater at your safety stop without the need to have any gas in your BC.  

If you have done this exercise at the beginning of the dive with a full tank then you have to do just a little bit of math - I promise, it is not hard.  A full, 80-cubic foot tank (which actually only holds 77.4 cubic feet at 3,000 PSI) contains about 6 pounds of air when full. As you breathe your air during your dive, the weight of your tank decreases. During a typical dive with an Aluminum 80 tank, you will lose 4-5 pounds of gas. Therefore, if you got perfectly weighted at the beginning of your dive - you would be 4-5 pounds underweighted by the end of your dive. The fix for this is simple: after completing the above weight check with a full tank, just add 4 pounds - so that you will perfectly neutrally weighted with an empty BC at the end of your dive. If you tank is significantly bigger or smaller, you may need to add a bit less or more weight. 

Tips for Weighting

• Perform a weight check at the beginning of every dive where you are using any new equipment. 

• Use an online estimator before you dive. This should get you in the right ballpark - so that when you get to the water you may only need to add or subtract a few pounds. Here's one to try: https://www.divebuddy.com/calculator/weight.aspx

• If you want to carry less lead, opt for a high pressure steel tank. Steel tanks are denser than aluminum ones, so they usually sink a bit even when empty - so you don't have to add as much lead to sink yourself and your kit. Steel tanks are common for cold water diving.

• If you are a cold-water diver, do not put all your weight in one place. Spread it out between a weight belt or harness, maybe a backplate, and a 2nd weight system like BC weight-integrated pockets, maybe even a few pounds in trim pockets. Spreading weight out throughout your body can help you achieve horizontal trim - and will help to ensure that your kit can float if you need it to (if you put all your weight on your kit, it may sink, even when fully inflated - which can increase your risk of issues).