(a) Applicability generally. This subpart applies—

1. (1) To the COFR Operator of—

   1. (i) Any vessel over 300 gross tons (except a vessel listed in paragraph (d)(1) or (2) of this section) using the navigable waters of the United States, or any port or other place subject to the jurisdiction of the United States, including any such vessel using a deepwater port or other offshore facility subject to the jurisdiction of the United States;
   2. (ii) Any vessel of any size (except a vessel listed in paragraph (d)(1) or (3) of this section) using the waters of the Exclusive Economic Zone to transship or lighter oil (whether delivering or receiving) destined for a place subject to the jurisdiction of the United States; and
   3. (iii) Any tank vessel over 100 gross tons (except a vessel listed in paragraph (d)(1) or (3) of this section) using the navigable waters of the United States, or any port or other place subject to the jurisdiction of the United States, including any such tank vessel using a deepwater port or other offshore facility subject to the jurisdiction of the United States;
2. (2) To a guarantor providing evidence of financial responsibility under this subpart on behalf of one or more of a vessel's responsible parties;
3. (3) To responsible parties other than the COFR Operator designated to represent the responsible parties for purposes of this subpart; and
4. (4) To any person serving as a U.S. agent for service of process under this subpart.

(b) How to apply this part to mobile offshore drilling units. For the purposes of applying the evidence of financial responsibility required under OPA 90 and this subpart and the limits of liability set forth in subpart B of this part, and in addition to any OPA 90 offshore facility evidence of financial responsibility requirements that may apply under 30 CFR part 553, a mobile offshore drilling unit is treated as—

1. (1) A tank vessel when it is being used as an offshore facility; and
2. (2) A vessel other than a tank vessel when it is not being used as an offshore facility.

(d) Exceptions.

1. (1) This subpart does not apply to public vessels.
2. (2) Paragraph (a)(1)(i) of this section does not apply to any non-self-propelled barge that does not carry oil as cargo or fuel and does not carry hazardous substances as cargo.
3. (3) Paragraphs (a)(1)(ii) and (iii) of this section do not apply to: any offshore supply vessel; any fishing vessel or fish tender vessel of 750 gross tons or less that transfers fuel without charge to a fishing vessel owned by the same person; any towing or pushing vessel (tug) simply because it has in its custody a tank barge; or any tank vessel that only carries, or is adapted to carry, non-liquid hazardous material in bulk as cargo or cargo residue.