Went to pull my boat out the other day and sunk the back end with my 80 Merc and boat 2/3's under the water after the trailer sank in some muck. An hour went by before we could get it out so I am wondering are gas tank vents designed to prevent water from getting in the tank? Its a round chrome vent that sits up about 1/2 an inch with 2 holes in the side. What do you call the stuff that checks for water in gas? Don't know if this is the right Forum but figured Merc guys would know. Thx for any help.