I think propane makes a lot of sense for a
dinghy outboard. Of course you would want to carry a spare canister onboard because unlike gasoline, you can't easily buy or borrow propane if you run out.
HopCar's post spells out the advantages.
Unfortunately, I bought the small
Honda gas
outboard three or four years ago (before the propane outboard was available, I believe) and unless it falls in the
water or gets stolen, it should last me the rest of my
boating days.
So I'm stuck with worrying about ethanol and stale gasoline and sloshing it around trying to fill the outboard while the
dinghy is bouncing around in the waves.