From what you describe, electric is economically viable, but marginal depending on what you value. My reasoning is that your fuel bill is ~$1000/mo and that would support roughly $70k of investment @12%.
How much do you have to carry, and do you have to go over 32 mph for an hour?? 75 hp for an hour would take about a 60kwh battery.??
That is heavy and costly enough to be questionable.
If you consider
-a lower speed
-a lighter more efficient boat -long stabilized mono (tri) operating at a lower multiple of hull speed or a foil assisted cat (lighter, higher speed)
you could dramatically reduce your power needs and cost.?
The kicker is that those big batteries could be very useful to your off-grid villa when not powering the boat.
If this boat must be big, heavy, fast, and conventional deep V, electric may be cost prohibitive.
