This part prescribes rules relating to the marking of structures, sunken vessels and other obstructions for the protection of maritime navigation.

(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.

As used in this part:

Hazard to navigation means an obstruction, usually sunken, that presents sufficient danger to navigation so as to require expeditious, affirmative action such as marking, removal, or redefinition of a designated waterway to provide for navigational safety.

High seas means those waters described in § 2.32(c) of this chapter.

Markings means the lights and other signals placed on or near structures, sunken vessels, and other obstructions for the protection of navigation.

Navigable waters of the United States means those waters described in § 2.36(a) of this chapter, specifically including the waters described in § 2.22(a)(2) of this chapter.

Obstruction means anything that restricts, endangers, or interferes with navigation.

Structures means any fixed or floating obstruction, intentionally placed in the water, which may interfere with or restrict marine navigation.