Do USN, USCG and DNR small boats use prop guards? They do a fair amount of rescue work so would seem to have a predictable general exposure to swimmers in the water.
Anyone know what kind of PFD? Have wrapped enough fishing line in props to see how easy that can be to do. Long trailing strap ends of a big PFD on a small size sailor? Harder to imagine with snug straps and tucked ends.
I am really a powerboater who doesn't sail much anymore. Used to teach adult sailing and have towed a lot of Sunfish etc. Props and swimmers are a hazard in the teaching scenario but similar issues with pulling skiers or tubers. Both realistically require powering to get the tow rope to the...