lot of current/heat when the circuit has, say, resistance for a 7 amp draw and a 7.5 amp fuse. I had this happen when a hot wire on my radar chaffed through and went to ground at the mast. The mast was connected to my bonding system and the end result was a little over ten thousand dollars worth of damage. I ended up replacing every one of my through hulls, prop shaft, prop, wiring in the mast (which had to be pulled) and bonding system. I also ended up in the Boat US insurance magazine as "one of those" featured articles.