stiebs
Contributor
kalvyn once bubbled...
While we were down, I was watching my Mosquito computer, which also gave me ~26 minutes. At about 2 minutes of NDT left by my Suunto, I signaled the DM by pointing at my computer, then up.
To parrot everyone else who has posted before me, listen to your computer. It may send you up earlier, but the consequences will be sending it into deco, and if you blow the stops, your computer stays on the surface for two days, or stays in guage mode for the remainder of your trip.
If you see the NDL time dropping down to the point where you feel you're going to blow it, ascend a few feet, and you will probably find that it will reward you and increase the NDL again.
Of course this may or may not be practical depending on the dive type.