The lines of distinction are becoming blurred today with dive electronics, much like phones & cameras. Most new DC's have gauge mode when the diver wants just monitoring. My Suunto D3 watch is a favorite for freediving and it's also has gauge mode, but it's not technically a dive computer, if gas uptake is your criterior. (It's already discontinued.) There are many new watch models sold by Oceanic, Suunto, Cressi-sub, Mares, etc. My Uwatec DC's, like many others, have optional alarms.
Having instruments has always been better than not.
Chad
Having instruments has always been better than not.
Chad