Engine battery disconnect necessary?

[Aerides]

Is there a requirement/recommendation to have the engine battery on a battery selector switch? Can I just have the starter battery cables go directly to the engine block and starter terminal without a shutoff switch?

I've got a traditional setup with a 1-2-both battery selector switch and 2 batteries. I'm planning on going to 2 big 6v deep-cycle batteries for the house and add a 12v starter battery. I've got restricted room in the engine compartment, with a battery tray on each side of the hull and can't put both 6v batteries next to each other on either side. If I have to go through a selector switch, it's about a 12' run from the panel where that currently is. I can put the engine battery about 2 feet away from the starter motor. I'm planning on connecting the 6v batteries in series with a total run of about 12 to 15 feet. For fusing I'm thinking of the ones that go directly on the + battery terminals (both 6v batteries).

[smac999]

It is an abyc requirement that every battery have a switch. Which is a North anerica thing. Your location is not listed.

What happens one day when your start soliniod fails or the start button. And the starter keeps cranking. I have seen it. It started a fire because there was no way for him to stop it. Only thing yiu can do is shut off the engine battery switch. If you have one. For the same reason the switch can not be in the engine room. But accessible outside of it.