Long Pond is a 211-acre cold water pond in Plymouth, Massachusetts, east of Myles Standish State Forest, Halfway Pond and Round Pond, west of Route 3 at Exit 3 and The Pinehills, northwest of Bloody Pond, and north of West Wind Shores. The pond has an average depth of 46 feet and a maximum depth of 100 feet. It is fed by groundwater and an inlet fr…Long Pond is a 211-acre cold water pond in Plymouth, Massachusetts, east of Myles Standish State Forest, Halfway Pond and Round Pond, west of Route 3 at Exit 3 and The Pinehills, northwest of Bloody Pond, and north of West Wind Shores. The pond has an average depth of 46 feet and a maximum depth of 100 feet. It is fed by groundwater and an inlet from Little Long Pond, and drains through the pond bottom. A paved boat ramp provided by the Public Access Board with ample parking spaces is easily accessible from Route 3. The Pond has a 50 hp limitation on boating.