Machias Seal Island is an island in disputed water between the Gulf of Maine and the Bay of Fundy, about 8.6 nmi southeast from Cutler, Maine, and 10 nmi southwest of Grand Manan Island, New Brunswick. Sovereignty of the island is disputed by the United States and Canada. The Canadian Coast Guard continues to staff a lighthouse on the isla…Machias Seal Island is an island in disputed water between the Gulf of Maine and the Bay of Fundy, about 8.6 nmi southeast from Cutler, Maine, and 10 nmi southwest of Grand Manan Island, New Brunswick. Sovereignty of the island is disputed by the United States and Canada. The Canadian Coast Guard continues to staff a lighthouse on the island; the first lighthouse was constructed there in 1832.