It could work
I believe that for the cruiser an electric tender may be an excellent choice. The 12 volts necessary to charge the battery can come from many sources, solar, wind, generator, or the main engine. No need to scout up gas in remote locations. I have used an electric trolling motor on an aluminum resevoir fishing boat for years, and can report that with a fresh group 27 battery it will power very nicely for 4 hours or so. I feel it is a great substitute for the typical 2 hp gasoline motor. Nothing is more silent when exploring the back waters. The down side is hefting a battery (as heavy as a larger outboard) on and off the tender for charging. It may be possible to bring the DC to the tender and leave the battery in place.Keeping this limitation in mind, I see no reason why it would not work.