Boats make houses look easy! With a house you have one feed (well, two if you have a generator & transfer switch) and multiple loads - all 110 (or doubled for 220).
Boats are worse by far. Power from shore power, engine alternator, generator, solar, and wind. 110V and 12V loads. Stored energy in batteries. Various devices to change from one to the other - enough to make a marine electrician go gray!