((a)) Except as otherwise provided in this section, a vessel to which this chapter applies shall be equipped with a double hull—

((1)) if it is constructed or adapted to carry, or carries, oil in bulk as cargo or cargo residue; and

((2)) when operating on the waters subject to the jurisdiction of the United States, including the Exclusive Economic Zone.

((b)) This section does not apply to—

((1)) a vessel used only to respond to a discharge of oil or a hazardous substance;

((2)) a vessel of less than 5,000 gross tons as measured under , or an alternate tonnage measured under as prescribed by the Secretary under equipped with a double containment system determined by the Secretary to be as effective as a double hull for the prevention of a discharge of oil;

((3)) a vessel documented under chapter 121 of this title that was equipped with a double hull before ;

((4)) a barge of less than 1,500 gross tons (as measured under chapter 145 of this title) carrying refined petroleum product in bulk as cargo in or adjacent to waters of the Bering Sea, Chukchi Sea, and Arctic Ocean and waters tributary thereto and in the waters of the Aleutian Islands and the Alaskan Peninsula west of 155 degrees west longitude; or

((5)) a vessel in the National Defense Reserve Fleet pursuant to section 57100.

((c))

((1)) In this subsection, the age of a vessel is determined from the later of the date on which the vessel—

((A)) is delivered after original construction;

((B)) is delivered after completion of a major conversion; or

((C)) had its appraised salvage value determined by the Coast Guard and is qualified for documentation as a wrecked vessel under .

((2)) A vessel of less than 5,000 gross tons as measured under , or an alternate tonnage measured under as prescribed by the Secretary under for which a building contract or contract for major conversion was placed before , and that was delivered under that contract before , and a vessel of less than 5,000 gross tons as measured under , or an alternate tonnage measured under as prescribed by the Secretary under that had its appraised salvage value determined by the Coast Guard before , and that qualified for documentation as a wrecked vessel under before , may not operate in the navigable waters or the Exclusive Economic Zone of the United States unless the vessel is equipped with a double hull or with a double containment system determined by the Secretary to be as effective as a double hull for the prevention of a discharge of oil.

((3)) A vessel for which a building contract or contract for major conversion was placed before , and that was delivered under that contract before , and a vessel that had its appraised salvage value determined by the Coast Guard before , and that qualified for documentation as a wrecked vessel under before , may not operate in the navigable waters or Exclusive Economic Zone of the United States unless equipped with a double hull—

((A)) in the case of a vessel of at least 5,000 gross tons but less than 15,000 gross tons as measured under section 14502, or an alternate tonnage measured under section 14302 as prescribed by the Secretary under section 14104, if the vessel is 25 years old or older and has a single hull, or is 30 years old or older and has a double bottom or double sides;

((B)) in the case of a vessel of at least 15,000 gross tons but less than 30,000 gross tons as measured under section 14502, or an alternate tonnage measured under section 14302 as prescribed by the Secretary under section 14104, if the vessel is 25 years old or older and has a single hull, or is 30 years old or older and has a double bottom or double sides; and

((C)) in the case of a vessel of at least 30,000 gross tons as measured under section 14502, or an alternate tonnage measured under section 14302 as prescribed by the Secretary under section 14104, if the vessel is 23 years old or older and has a single hull, or is 28 years old or older and has a double bottom or double sides.

((4)) Except as provided in subsection (b) of this section—

((A)) a vessel that has a single hull may not operate after ; and

((B)) a vessel that has a double bottom or double sides may not operate after .

((d)) The operation of barges described in subsection (b)(5) outside waters described in that subsection shall be on any conditions as the Secretary may require.

((e))

((1)) For the purposes of this section, the gross tonnage of a vessel shall be the gross tonnage that would have been recognized by the Secretary on , as the tonnage measured under , or as an alternate tonnage measured under as prescribed by the Secretary under .

((2)) This subsection does not apply to a tank vessel that, before , had undergone, or was the subject of a contract for, alterations that reduce the gross tonnage of the tank vessel, as shown by reliable evidence acceptable to the Secretary.