The most effective tool to have available in the event of a heart attack is a defibrillator - together of course with the skills to use it. Current models are almost "idiot proof", and (in first world terms) relatively affordable. The ranger at Hol Chan should have one on his boat, with the skills to use it. That might mean he'd need a larger boat, as the patient needs to lie flat. I'm sure their income has dropped along with that of the rest of us, but a way should be found.

Diane's point about Hol Chan not always being ideal for the people who visit it is well made. On Ambergris Caye we should perhaps push Mexico Rocks as a more suitable venue (no current), and I believe there's a comparable place between Caye Caulker and Hol Chan. At busy times Hol Chan is simply too busy anyway.