Code of Federal Regulations Title 33. Navigation and Navigable Waters § 33.165.111 Safety Zone:  Boston Harbor, Boston, Massachusetts

(1) Around the U.S.S. Constitution or any accompanying parade vessels when Constitution is under way—300 yards in all directions in the waters around the U.S.S. Constitution and each parade vessel accompanying Constitution whenever the U.S.S. Constitution is underway in Boston Harbor from the time such vessels depart their respective berths until the time they complete their transit and are safely moored.

(2) Whenever Constitution is moored at Pier 1, Charlestown Navy Yard—the waters between Hoosac Pier and Pier 1, Charlestown Navy Yard, from the imaginary line connecting the outer easternmost point protruding into Boston Harbor from Hoosac Pier to the outer westernmost point protruding into Boston Harbor from Pier 1, Charlestown Navy Yard, extending inbound along the face of both piers to the landside points where both piers end.

(3) Around the U.S.S. Constitution—fifty yards in all directions in the waters around Constitution when the vessel is moored at any Boston berthing location other than Pier 1, Charlestown Navy Yard.