Definitions for "Dive computer"
an electronic device used by a scuba diver to measure the dive profile (depth, bottom time etc) and to display information needed for a safe
an electronic instrument that replaces and expands on the functionality of depth gauges and bottom timers (and more frequently now, pressure gauges)
Device that does all the had work for you. No more multi level diving calculations, no more PADI wheel - based on empicic data and theoretic models - not necessarily always right but a great help for repetitive diving. Beeps often.
Keywords:  gadget, sports, worn, wrist
a sports gadget that is worn on the divers wrist
a reliable tool for extending dive time and increasing dive safety