Hola,
I dived Speigal Grove last year and was a very large and big wreck.. I had computer, but one diver on the boat got lost and surface off wreck with no safety stop. It scared us.
Dive boat had to uproute from the mooring and motor over as the diver was a little upset and of course when they come on the boat ladders and to their bench, they were piss off, but he wasn't wearing a computer and ran out of air. He had not buddy and decide not to swim to the boat, because holding the line on the starboard side of the wreck mid ship was his safety net.
I can see why boats like that want a computer and think that the divers can rent or buy one, as if they should get one for free. If everyone keep getting free dive gear to rent, where does it end? Free tank, Free doubles, Free Canister Light? It is our responsibility to have our gear stowed and have it ready to dive, no matter what.
Back at home, when we dive off the coast of Akumal, everyone best be having computers, because the wall goes too deep for dive table and people don't watch their depth gauge. A computer will be helping the entire situation.
Julio