The term tank vessel means a vessel that is constructed or adapted to carry, or that carries, oil or hazardous material in bulk as cargo or cargo residue, and that—
(a)
Is a vessel of the United States;
(b)
Operates on the navigable waters of the United States; or
(c)
Transfers oil or hazardous material in a port or place subject to the jurisdiction of the United States.
Code of Federal Regulations
[CGD 79-116, 62 FR 25135, May 8, 1997]