on my 27 ft. hunter i have a slow but steady leak from forward ground wire hole in bilge. it has been leaking now for 4 days since i went into water for season. it is near fresh water tank , but tank was emptied last year and i poured antifreeze into tank to see if antifreeze was visable in leak but it was not. could this be snow melt water but water does have salty taste. all visable compartments are dry and not coming from shaft etc. thanks