I know this was just a hypothetical question but as a scuba diver I actually pay for a completely separate insurance on top of my standard health plan called DAN insurance: http://www.diversalertnetwork.org/insurance/dive/
So stuff like a helicopter evac, access to a hyperbaric chamber and the ability to call a number and speak to a doctor who specializes in diving related illness means I already do pay more for insurance than someone who isn't a diver.
So stuff like a helicopter evac, access to a hyperbaric chamber and the ability to call a number and speak to a doctor who specializes in diving related illness means I already do pay more for insurance than someone who isn't a diver.