Tom,

It already is a requirement for house banks and has been for a long time. They want the fuse within 7" (wire distance) of the battery bank. The 7" part is a little ridiculous but the point is the same, house banks need to be fused if you are a new boat builder, and it's a good idea for everyone else.

Start banks are excluded because the electrical PTC can't agree on a cut off based on engine size etc.. At some point engines get to big for the easily available & affordable fuses. I always fuse both start and house banks on small sailboat AUX engines. The big problem with this, and I have gone around and around with John A., is that sooo many boats are equipped with a 1/2/BOTH/OFF switch that technically EITHER bank can be house or start. Many builders even ship their boats with identical batteries so which one is "house"? Either way builders generally only ship with just one bank fused as that is the "requirement".

They are looking into start bank requirements/fusing/conduit etc. again especially with the advent of Lithium technologies. This was found on a boat I made some new battery cables for just last week. Fortunately the boat already had MRBF's installed BUT chafe can happen even on the best maintained boats. This cable was NOT very far away from a dead short and I see this sort of thing very often.