McP, a couple of points. There is never any “condensation” in modern gas tanks. They are sealed and pressurized. All venting is out-gassing through the carbon canister…Todays fuel contains 10% ethanol…If ANY appreciable amount of water contaminates the fuel, the whole mess separates, “phase separation” I think they call it…It must then be drained from the tank. Today, because of the ethanol, Marinas are plagued with this problem because of the poorly sealed marine gas tanks and leaky deck fittings…