Abstract: A compact inline unitized plug/receptacle adapter interconnects a four blade plug configuration with a three slot receptacle thereby allowing a boat or RV user to readily adapt to an available receptacle at mooring or camping sites while retaining the ability to utilize the electrical equipment therein. The adapter includes a cover assembly carrying on the outer end the three blades for connection with a host receptacle and carrying on the inner end the four terminals for connection with the guest plug. The live or hot terminals are interconnected by a jumper bus mounted at a raised pad on the cover and electrically connected with the live blade. The neutral and ground terminals are separately connected with their respective blades and mounted at pads of differing elevation on the cover thereby providing differing base elevations and a first degree of physical and electrical insulation between the hot and neutral/ground paths.