Dive computers store critical information about your previous dives so you can access the information when needed. This eliminates the need to document this information during and immediately after a dive, and is especially useful when documenting your dives in a logbook.

Most dive computers include an altitude compensation feature that adjusts your no-decompression limits when diving at high altitude. This eliminates the need to use special altitude adjustment tables that would otherwise be required to plan the dive.

Your body's various tissues ingas and offgas nitrogen at different rates, and the rate changes with your depth. This means that as you ascend to shallower water, certain tissues may offgas nitrogen while others continue to ingas nitrogen.

Computers are able to monitor nitrogen levels in various hypothetical tissue compartments, and base your remaining dive time on the compartment with the highest nitrogen level. This provides more accurate time limits, as well as increased dive time.