Engineering360: "Video: World speed record chased by electric outboard powertrain system"

One gallon of gasoline contains approximately 36 kW-hr of thermal energy.

The battery pack of this vessel is rated at 60 kW-hr. That's a little less than two gallons of gasoline in thermal energy.

Factoring in the efficiency of a high-performance gasoline engine (~20%), that means you can store the same effective motive energy with about ten gallons of gasoline.

I'm guessing this boat isn't going to travel very far.