Rupert BayRupert Bay is a large bay located on the south-east shore of James Bay, in Canada. Although the coast is part of the province of Quebec, the waters of the bay are under jurisdiction of the territory of Nunavut.GeographyThis bay has a width of and a length of. It is the largest arm of James Bay. The Rupert, Nottaway and Broadback Rivers empty into this bay. The Cree village of Waskaganish is on the eastern shores of the bay.