Many vehicles such as boats and other marine crafts have fuel systems that require venting. For example, venting a fuel tank equalizes the pressure in the tank by releasing fuel vapors and allowing atmospheric air to flow into the fuel tank so that the liquid fuel can be drawn from the tank via suction. Some venting systems employ a separate venting tube or line to vent the fuel tank, while other venting systems employ a venting tube in combination with a filling device. Although a separate vent tube prevents the buildup of fuel pressure within the tank, it does not prevent contamination of the environment as a result of unintentional overboard venting of liquid fuel, which frequently occurs when a marine fuel tank is being refueled due to fuel tank overfilling and/or due to splashing, sloshing or other fuel surges during boat movement. Additionally, separate vent tubes are prone to allow the ingress of water and other contaminates into the fuel stored in the tank, which can lead to engine damage.