Swan's Island and Placentia Island at its entrance; the town of Blue Hill lies at the far end.[1] Morgan Bay, Union River Bay, and Western Bay empty into it. Long Island in the north of the bay is the largest uninhabited island in Maine.[2]
Due to its protected waters, Blue Hill Bay is popular with recreational boaters.[2] In addition to crab, lobster, and other fisheries, aquaculture of salmon and mussels is practiced in the bay.[3][4] The shores of the bay are an important breeding ground for harbor seals.[5]