Maybe 20 or 30 years ago you could get away with claiming that jets are less efficient than stern drive, but not today. They are much more...
Anything is possible theoretically and I do not know of a capable electric motor and battery combo today that could be a commercial success....
I'd be siding with CDK to a point. There are a number of diesel/gas/electric hybrids that I have been involved with that are Hamilton Jet driven....