Title 46 › Subtitle II — Vessels and Seamen › Part B — Inspection and Regulation of Vessels › CHAPTER 37 — CARRIAGE OF LIQUID BULK DANGEROUS CARGOES › § 3703a
Tank vessels that carry oil in bulk must have a double hull when they operate in U.S. waters, including the Exclusive Economic Zone, unless an exception applies. Exemptions include vessels used only for oil-spill response, vessels under 5,000 gross tons that have an approved double containment system, vessels already fitted with a double hull before August 12, 1992, certain barges under 1,500 gross tons carrying refined petroleum in parts of the Bering, Chukchi, and Arctic Seas and nearby Alaskan waters west of 155 degrees west longitude, and vessels in the National Defense Reserve Fleet. A vessel’s age is counted from the later of when it was first delivered, when a major conversion was finished, or when the Coast Guard set its salvage value and it qualified as a wrecked vessel. Small vessels with building or conversion contracts before June 30, 1990 and delivered before January 1, 1994, and vessels with Coast Guard salvage appraisals before June 30, 1990 that qualified as wrecked before January 1, 1994, must have a double hull or an approved double containment to operate in U.S. waters. Older vessels in three tonnage groups must be fitted with double hulls at certain ages: for 5,000–14,999 gross tons, a single-hull at 25 years or a double-bottom/double-side at 30 years; for 15,000–29,999 gross tons, the same 25- and 30-year cutoffs; for 30,000 gross tons or more, a single-hull at 23 years or a double-bottom/double-side at 28 years. Single-hull vessels may not operate after January 1, 2010, and vessels with only a double bottom or double sides may not operate after January 1, 2015. Gross tonnage is measured as the Secretary would have recognized on July 1, 1997, unless reliable evidence shows an earlier alteration reduced the tonnage.
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Legislative History
Reference
Citation
46 U.S.C. § 3703a
Title 46, Shipping
Last Updated
Aug 21, 2026
Release point: 119-102