WOAH !! That is not a good one! Sorry to hear that, Vezel. Battery terminals on boats in general will work themselves loose because of the wave motion and because boats typically vibrate more than cars do. Once the terminal gets a little loose, the heating from the bad connection will thermally cycle the connection and add another loosening tendancy.. It will continue to loosen until it will get really hot when passing lots of amperes, like starting, and could cause a fire.. Good to check/clean/retighten battery terminals every couple of years or so.. Another thing that can happen is a battery explosion when a battery has been charged hard or discharged hard and a small spark occurs at a terminal because of a bad connection.. again bad connection is the key..Can be either positive or negative connection. No ball of green gunk is necessary.. Can and will happen at the starter connection, the engine ground strap, and the battery selector switch as well. Probably not specific to H 336, unless there is a strange kind of battery terminal that is unique to that boat..?? Oh yeah.. could be a bad crimp-on terminal too.. the copper wire end that bolts to the connector.