Well my starter boat just had a battery for the engine and a single 120 ah battery for everything else. Enough for a few days out, more if you run the engine some of the time for recharge, but a few days is about the limit.

The new one will have, depending on room and such, 3-5 batteries plus the engine battery. Enough for maybe a week, and with the engine recharging everything whenever I'm on the move should be more than enough to cover any reasonable needs.