first yes electric has different power curves than a diesel. electric motors produce more torque at low rpms and are more efficient at high rps. so at cruising speed or close to it when the wave hits you the electric wont have the torque to get you moving again, where as a diesel is just all torque.
cars are different story, mostly because of drag. a sailboat like my hunter 27 needs 8 hp to get to 5.2 knots ( need a bottom job ) or so, a car with 8 hp in a diesel motor could get to 55 mph or so if the areo is good.
my hunter has an 18 gallon tank and at cruise can run for about 10 days, not hour but days. the c22 listed can do 4 knots for a few hours, and would take one or two days to recharge with a 1000 bucks in solar (assuming 100 amp hours used ). this is not counting currents or winds.
i think it will be a hybrid system, one that can motor for an hour, then needs a genny to keep going.
as for the tesla battery, if it costs about 400 bucks for 60 or so watts of solar. and we use 480 watts of panels at about 3200 bucks. that will produce about .5k watts ( if perfect ) of juice per hour, or about 112 hours of sunlight to charge. so you can, if the boat drains the battery in one day sail of low to no winds, you can use you boat once every 10 days with full summer sun, or about every 20 days in the fall or spring
hydro drag is a pain in the math