How to read dive tables and calculate safe limits

Dive tables are an essential tool for every recreational diver and help with safe planning of multiple dives in one day.

Why you need dive tables

Compressed air carries nitrogen that accumulates in the tissues during the dive. If you ascend quickly or dive a lot in one day, you may suffer decompression sickness.

Components of dive tables

Residual nitrogen pressure
It is expressed with letters from A to Z and tells you how much nitrogen remains in your body after the dive.

Surface interval time
The time you must wait between two dives to off-gas excess nitrogen.

No-decompression limit
The maximum time you can stay at a given depth without needing decompression stops.

The electronic dive computer

Most divers today use a digital dive computer worn on the wrist. It calculates everything automatically and alerts you to safe limits.

Decompression stops

• A stop at 5 meters for 3 minutes on any dive
• A longer stop when approaching the allowed limit
• A full rest of one hour between every two dives

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Tables and the computer are not just numbers. They protect your health and your life underwater.