If your dive computer fails underwater or becomes unusable due to battery depletion, terminate the dive immediately and begin a controlled ascent. Do not exceed the maximum ascent rate specified by your computer. A typical maximum ascent rate is 10 metres per minute.

After surfacing, do not dive again or board an aircraft until nitrogen has been completely eliminated from your body.

As a theoretical guideline, complete nitrogen elimination requires approximately six times the maximum tissue half-time indicated in the dive computer’s operating manual.

Typical maximum tissue half-times used in dive computers are 360 minutes (6 hours) or 720 minutes (12 hours). Therefore, a waiting period of approximately 36 hours or 72 hours may be required for complete nitrogen elimination.