I understand where gianaameri is coming from; I volunteer one day every two weeks in a nearby aquarium, feeding fish and cleaning windows and fake coral. We do not use computers or timers because the max depth is 13 feet and with a single tank we can't get into deco...so bottom time and dive depth are irrelevant in this fixed, known, non-threatening situation.
However, we are not in an overhead environment (mostly) and there is a tender watching for us at all times. In fact, we are not let in the water solo...we have to wait for another diver, and the tender.
So I understand his principle of not needing the usual electronics....but not his practice. Solo or overhead would seem to make the practice inappropriate. He did both. Even if he could not have gone into deco, it is an environment that can keep you in it....entanglements, falling ceilings, severe cramps, whatever, with no immediate access to the surface. For me, his issue is running out of gas in an overhead environment. He says, how could the electronics have helped? They couldn't have, but at least it would give him something to look at as his minutes tick away. :reaper: