Question 1

How much weight do I need for scuba diving?

Accepted Answer

As a general rule, a diver needs approximately 10% of their body weight in lead when diving in a standard 5mm wetsuit in salt water. However, this varies based on your gear; for example, a drysuit requires significantly more weight, while a thin skinsuit in freshwater requires much less.

Question 2

Do I need more weight in salt water than fresh water?

Accepted Answer

Yes, you need more weight in salt water because it is denser and provides more lift. To compensate for the increased buoyancy, you typically need to add 2.5% to 3% of your total body weight in lead when moving from a lake to the ocean.

Question 3

How does an aluminum tank affect my buoyancy?

Accepted Answer

Aluminum tanks (like the standard AL80) become positively buoyant as they empty. A tank that is nearly empty can provide about 4 lbs (1.8 kg) of lift. Our calculator accounts for this "tank swing" to ensure you stay underwater during your safety stop at the end of the dive.

Question 4

Why am I struggling to stay down at the end of a dive?

Accepted Answer

This is usually caused by "under-weighting" or failing to account for tank buoyancy changes. As you breathe air from your cylinder, the tank becomes lighter. If you didn't include enough lead to offset a near-empty tank, you will become too buoyant to maintain depth during your safety stop.

Scuba diving weight calculator

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