johnnythan - if price were not a factor, I'd suggest that the Citizen Hyper Aqualand would come close to meeting the requirement: Automatic (water) activation & termination, maximum depth, average depth, temperature, and start & end times. Built-in stopwatch function as well. Unfortunately, price probably is a factor, since you could buy at least two traditional bottom timers, with change left over. You could also buy a Viper, & put it into permanent gauge mode for the same price.
I thought all the bottom timers were made by the same manufacturer, and re-badged. Does anyone know if they are still being manufactured at all?