Various types of electric powered boats will certainly become realistic, just not right now for most of us due to current battery limitations.
It's similar to electric vehicles, especially tow vehicles. Electric trucks and SUV's are fine right now without a trailer in tow, but add 5,000-15,000 pounds and your range drops to 25-50%. Fine for heading from home to a local boat ramp, but forget about towing for a couple of hours. Truck salesmen have given me various statements:
- It might work for you, but I don't recommend it as a tow vehicle.
- Oh, no, don't do it; you won't be happy.
- Nope, it won't work. How about our shiny new hybrids?
FD