(a) Except as provided in paragraph (b) of this section these rules apply to:(1) Structures located in or over waters subject to the jurisdiction of the United States and, on the high seas, structures owned or operated by persons subject to the jurisdiction of the United States;(2) Sunken vessels in the navigable waters or waters above the continental shelf of the United States; and(3) Other obstructions existing on or in the navigable waters or waters above the continental shelf of the United States.(b) The following obstructions are exempt from the requirements of this part:(1) Dredging pipelines subject to subchapter E of this chapter;(2) Bridges subject to subchapter J of this chapter;(3) Vessels subject to the International Regulations for preventing Collisions at Sea, 1972 (1972 COLREGS) or the Inland Navigation Rules;(4) Deepwater port facilities subject to subchapter NN of this chapter; and(5) Artificial islands and structures subject to Part 67 of this subchapter.CGD 78-156, 48 FR 11267, Mar. 17, 1983, as amended by USCG-2016-0498, 82 FR 35080 , July 28, 2017