I just spoke with with one the dive shop owners. Details as I know them...
66 year old gentleman, on the wreck of the Caroline Rose, which is at best an intermediate dive. Apparently there was a fairly strong surface current and coroner has tentatively called cause of death as heart attack.
The victim was on the surface and swimming back to the boat. He was towed in by other divers, and CPR was commenced. Presumably he was transferred from the dive boat to town by either Coast Guard or Fathom Five Park vessel. In either case, this would be about a 20 minute trip, give or take. The wreck lies in about 55' and was purpose-sunk some years ago. It is outside the Park boundary in a somewhat sheltered bay. The Caroline Rose is perhaps most famous as her likeness appears on the reverse side of the Canadian $100 bill.
The boat was the Deep Obsession operated through Divers Den. The "Deep O" is probably the nicest dive boat in town, with a capable crew. Divers Den is a well run shop, although in the interest of full disclosure, I will mention that the shop was recently purchased by good friends of mine, from other friends of mine. The boat is still owned by the previous shop owner, as I understand things.
Apparently the victim had recently returned to diving after an absence. He completed a refresher course recently. I don't know the length of his absence from the sport, nor do I know anything of his qualifications or his experience. I also don't know how many, if any dives he had completed since the refresher, nor do I know if this was the first dive of the day. (Typically, the Caroline Rose is not a "first dive of the day".) I think it's reasonable to think that if he did a refresher, that he probably hadn't logged a ton of dives previously.
This very much sounds like one of those "Death while diving" as opposed to "Death from diving" which is becoming more an more common.
I spoke at a conference this spring and was followed by Dr. George Harper who is also the coroner for the Tobermory area, and he spoke at length about this becoming the most common case of "diving accident"... aging diver, died while diving from a cardiac event.
At this time, I do know know any details about the deceased, but it doesn't sound like there is much to be learned here, other than we old folks need to stay fit!