Penobscot Bay

Inlet of the Atlantic Ocean at the mouth of the Penobscot River, 40 km/25 mi south-southwest of Bangor, in central Maine. Measuring 56 km/35 mi from north to south and 8–32 km/5–20 mi from east to west, Penobscot Bay contains numerous small islands.

The irregularly shaped bay heavily indents the rugged, granite coastline. Fishing, lobster-catching, and tourism are the main industries here. The principal harbours are Stonington (on Deer Isle), Castine, Bucksport, Searsport, Belfast, Camden, and Rockland. Vinalhaven Island lies at the mouth of the bay, and Isle au Haut is 16 km/10 mi to the east. Hurricane Island, a tiny island 6 km/4 mi southwest of Vinalhaven, is the site of an Outward Bound school. Holbrook Island Sanctuary State Park and other refuges on the islands are home to many marine birds. Camden Hills State Park borders the bay on the west.