What do most of you do about the vent on a plastic fuel tank when your boat is not going to be used for a week or two?<br />Obviously the same problem comes up with my second tank when I am not using it.<br />One of my concerns was getting water in the tank by having the vent open during rain or while running and encountering water splashing on the fuel tank.<br />When I closed the vents, the tanks expanded like a balloon which didn't seem to be a good thing.<br />I now leave the vents open all the time, but still worry about letting water in.<br />Do the vent systems have a check valve or baffle that will prevent the rain or splashed water from entering the tank?<br />The tanks in question are 2 Tempo, 6 gal, on a pontoon boat.<br />Charles 
