Yep, that is feasible today. Coastal ferries and routes counted in hours. Here's a larger ferry connecting Sweden and Denmark that was converted to hybrid with

Yep, that is feasible today. Coastal ferries and routes counted in hours. Here's a larger ferry connecting Sweden and Denmark that was converted to hybrid with the goal to not use any diesels in regular service. Has 4 160 kWh battery capacity, one trip takes 20 minutes and uses 1 175 kWh. https://www.youtube.com/watch?v=UyWcY4bTdl8 https://www.youtube.com/watch?v=UyWcY4bTdl8 A company specializing in it is https://corvusenergy.com/ https://corvusenergy.com/