I am sorry but a 3/8 nut should not look like this. They invented wrenches so we can PROPERLY tighten nuts. A set of pliers is not the same as a wrench. I have no idea what type of pliers or tools were used to install this nut, perhaps even a pair of lobster shell crackers, but it was simply not done properly or safely...


Please be careful out there. It only takes a few moments of inattention or some poor practices to get your boat burned to the waterline. This disaster waiting to happen was narrowly averted and no amount of over-current protection would have prevented a full meltdown if this had been allowed to persist.