Abstract: A fuel system, particularly adapted for boats, includes a releasable coupling for connecting a tube or hose between the fuel tank and the engine. The coupling includes a fuel valve and a vent valve both adapted to automatically open and close respectively upon connecting and disconnecting mating parts of the coupling. The vent valve is adapted to open before the fuel valve is opened for venting any pressure head within the tank which is likely to cause leakage in the fuel hose or tube, such venting taking place through both mating parts and through the hose to a location remote from the tank.