Distance from the panel requires a separate main breaker/fuse. By memory 10 feet or more, but don't quote me.
Also are you using a 50 AMP power supply cable and dock breaker? If only 30 amp then these fuses need to be 30A.
You only need one working engine. That is why I have two.
Sea Sanctuary-new to me 1992 Bayliner 4588