, an inlet of the Bay of Fundy in northeastern North America. It is at the mouth of the St. Croix River, between Maine and New Brunswick, Canada. The bay is separated from the Bay of Fundy by numerous small islands, including Deer Island and Campobello. It is about 30 miles (48 km) long and 20 miles (32 km) wide and has high tides averaging 18 feet (5.5 m). Several proposals have been made to construct a hydroelectric plant here, using the tidal action to generate power.