Positive buss bars are seldom used after the
electrical system is installed. It is not for individual pieces of
equipment to be attached to. Your circuit breaker or fuse panel(s) are for that. If
power is need at
remote sections of the boat additional sub-panels with both ground and hot (with breakers/fuses) installed in that area.
My boat does have a positive buss bar for the house
batteries that allows the
windlass and the
generator starter to be taken off before the main hot cable goes to the master panel.
Then there are several sub-panels : one for lower station
electronics and stereo, another under the aft
deck for
electric reels, wash down
pump,
fuel polisher. Another set of sub-panels for each
engine handle all the
electric losds needed to run the engines ( each
engine it’s own) for things like
exhaust overheat
alarm,
fuel shutoff solenoid, hour meter, synchronizer, instrument gauges. All too much to try snd run directly off the key switch. Key switch turns on a solenoid and powers up the little run panels and takes the load off the key switch and makes fusing each much easier than a bunch of inline
fuses that are a hassle to deal with.