1. Stay Warm
If you dive uninsulated, you’re heating the ocean with your body, which increases your metabolism and oxygen-burn rates. Experiment with different amounts of protection.
2. Go Slowly
Rapid, jerky movements burn more air due to increased resistance underwater.
3. Look, Ma, No Arms!
Imagine you’re a Tyrannosaurus rex, with huge legs and tiny little arms. Waving your arms and hands around burns incremental air, with little or no impact on your position.
Read the entire article at Scuba Diving Magazine