33 C.F.R. § 334.40
Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target area
(a) The danger zone. A circular area with a radius of 500 yards having its center on Shag Rock in the vicinity of Duck Island at latitude 43°00′12″, longitude 70°36′12″.
(b) The regulations. (1) No person or vessel shall enter or remain in the danger zone from 8:00 a.m. to 5:00 p.m. (local time) daily, except as authorized by the enforcing agency.
(2) This section shall be enforced by the Commandant, First Naval District, and such agencies as he may designate.