Yeah this is much more in common with the Baysian scene than the Wisconsin. There's not much to penetrate on the Wisconsin (well a little). When he didnt return within the hour dive and his wife made the initial call-out he'd almost for sure already passed. At 72 I would not be surprised if heart disease was a factor.There has been two situations in the last 30 years were divers have been trapped on a great lakes wreck where it was several hours before a rescue was conducted. One was on the Regina in 2000 where two divers got lost and silted out in the bow. The one diver was still alive and bottles were given to him through a porthole, but when extraction time came, he ran out of air and drowned in the wreck. The next more famous one was on the wreck of the Cedarville. Diver got lost and then trapped himself behind fallen debris in panic. Same situation with bottles being handed into a port hole over a two hour time span.
On the Regina, a seaeye ROV was used to try and locate the victims. If a Cedarville repeat happened again, our ROV would hopefully be able to locate the diver before his supply runs out. We would be able to get him on surface supply air for the time being.
Glad to hear you have access to ROVs and surface supply in these somewhat unique penetration situations