Re: Mast wiring tip needed.
Yes, you have to run the hot wire from the fuse panel. There is no positive buss-- if there were such a thing you'd need to wire a switch after the bus to a convenient spot anyway.
On my boat the negative buss is under the forward dinette cushion, to port of the mast step. There is a fuse panel above the galley sink which has a "steaming light" fused switch. Positive goes from there to a connector under the dinette. This connector is actually a "segmented" bus bar which allows multiple separately fused circuits to be connected in one location. This is convenient to have under the dinette so all 12V mast connections can be connected in one area. I also run my bilge pumps to that bus.
If you find a similar separated-circuit bus bar in your dinette, just test each circuit while you try switches at your fuse panel. I suspect that it's already wired but may be unused for whatever reason.
1977 C&C 30 Mk 1 hailing from Port Clinton, Ohio