Bob, on my 245 I noticed a similar black fuse box next to my battery switch inside the bilge access door to the starboard side of the live well. I haven't investigated that yet. I assume its the same thing?
OK so my #1 Batt supplies constant power to the aft and forward bilge float switches and the stereo memory circuit. The 40 amp breaker supplies switched power to the helm panel and the trim tabs.
What a lot of owners don't realize is that the 40A breaker has absolutely nothing to do with the other fuse, except for the tabs. The other fuses are fed straight from either the batt or the batt switch...So have another George and digest the drawings...