In the "Diving Equipment" chapter, you learned that weights are worn to offset the buoyancy of your body and exposure suit. Lead weights are used because their density allows us to add weight without significantly increasing our volume. The following are just a few of the factors that determine the amount of weight you'll need to achieve neutral buoyancy.

Salt water is denser than fresh water; so more weight is required for dives in salt water.

If you're overweight, you'll require more weight because fat tissues are less dense than muscle tissues. And since most bodies are naturally buoyant, larger people will require more weight than smaller people will.

Water temperature has an indirect effect on buoyancy because you'll be wearing a thicker, more buoyant exposure suit in cold water.