James Bay is the southern arm of Hudson Bay in northeast Canada. The bay was named for the English navigator Thomas James. James explored the bay in 1631 and again in 1633 while trying to discover the Northwest Passage. James Bay lies in Ontario and Quebec. It is about 300 miles (480 kilometers) long and 140 miles (230 kilometers) wide. Many islands lie in the bay. Akimiski, the largest, covers about 1,160 square miles (3,000 square kilometers). Several large rivers flow into the bay, among them the Attawapiskat, Albany, and Moose in Ontario; and the Harricana, Nottaway, and Eastmain in Quebec. See also Hudson Bay .