In theory you could run the gas engine and use the electric as a trolling generator to recharge the battery (but I'm sure it wouldn't be very efficient if it worked at all).
I'm hoping I can run the trolling motor and then lower the outboard, spin the prop backwards, suck in air thru the exhaust, and regenerate gas dripping out the carburetor and back into the tank.
At least, that's what the YouTube video I watched said would happen. .
But seriously, the prop on this thing looks really terrible for regen, plus not using the outboard unless really needed for a rescue situation or something was sort of the point anyway.
In the future through, when it's out of warranty I could see trying it out for regen while under sail on the Catalina.