Negative busbar ?

I'm thinking of setting up a "negative busbar" closer to the battery compartment to complete the circuit to the washdown, livewell pumps, bulge and some astern courtesy lighting. The normal negative lead to the front panel (a larger guage) would remain and be used for electronics, horn, navagation lighting etc. Positive leads, circuit breakers and switches remain at the helm. I'm trying to improve and upgrade the wire size on that equipment without running everything back and forth to and from the helm. Are there issues I'm missing?