49 U.S.C. § 13521 General jurisdiction
(a) General Rules.—The Secretary and the Board have jurisdiction over transportation insofar as water carriers are concerned—(1) by water carrier between a place in a State and a place in another State, even if part of the transportation is outside the United States; (2) by water carrier and motor carrier from a place in a State to a place in another State; except that if part of the transportation is outside the United States, the Secretary only has jurisdiction over that part of the transportation provided—(A) by motor carrier that is in the United States; and (B) by water carrier that is from a place in the United States to another place in the United States; and (3) by water carrier or by water carrier and motor carrier between a place in the United States and a place outside the United States, to the extent that—(A) when the transportation is by motor carrier, the transportation is provided in the United States; (B) when the transportation is by water carrier to a place outside the United States, the transportation is provided by water carrier from a place in the United States to another place in the United States before transshipment from a place in the United States to a place outside the United States; and (C) when the transportation is by water carrier from a place outside the United States, the transportation is provided by water carrier from a place in the United States to another place in the United States after transshipment to a place in the United States from a place outside the United States.
(b) Definitions.—In this section, the terms “State” and “United States” include the territories and possessions of the United States.