Be familiar with your fuse block. Know which fuse feeds which circuit. Time is valuable in competition something you don't need to be wasting tracing out electrical circuits. Carry several replacement fuses in all the sizes that your boat requires. Failure to do so will tempt you bypass the fuse or to plug in an over-sized fuse, creating a potentially hazardous situation.
Some tournaments refuse to weigh dead fish.
Weight is too hard to come by and you certainly don't need your weight penalized by having dead fish. Aside from your personal loss, you owe it to your draw partner to have your equipment in good shape so that he takes no penalties. If you support catch and release, the other benefits are obvious. Carry a spare of every thing. Carry a spare trolling motor prop, shear pins, and shaft nut.