46 U.S.C. § 60301 — Regular tonnage taxes

(a) Lower Rate — A tax applies at 4.5 cents per ton (capped at 22.5 cents per ton per year) for fiscal years 2006 through 2010, and 2 cents per ton (capped at 10 cents per ton per year) for every fiscal year after that, on each entry into a U.S. port by (1) a vessel arriving from a foreign port in North America, Central America, the West Indies Islands, the Bahama Islands, the Bermuda Islands, or South America's Caribbean coast; or (2) a vessel returning to the same U.S. port it left, without entering the U.S. anywhere else — except (A) a vessel of the United States, (B) a recreational vessel (as defined in section 2101), or (C) a barge. (b) Higher Rate — A tax applies at 13.5 cents per ton (capped at 67.5 cents per ton per year) for fiscal years 2006 through 2010, and 6 cents per ton (capped at 30 cents per ton per year) after that, on a vessel entering a U.S. port from a foreign port not named in subsection (a)(1). (c) Exception for Vessels Entering Other Than by Sea — Subsection (a) doesn't apply to a vessel entering other than by sea from a foreign port that doesn't impose tonnage, lighthouse, or similar taxes on U.S. vessels.