Scuba diving is a pretty risky activity on the scale of things that rich people do in their everyday life. Golf and cycling are a lot safer.

Scuba fatalities fall into a few buckets, the big two are inexperience/bad decision making, and older folks with health issues (underwater heart attacks/respiratory distress, basically).

As a former dive pro, an overweight 63 year old is someone that I would keep a very close eye on while diving.

The odds are pretty low, but there is a reason that many life insurance companies exclude scuba divers from their coverage.

That said, I'm happy to let him live as dangerously as he wants, he deserves it.