33.—(1) Article 4 applies to an activity to the extent that it is carried on in exercise of a right under rules of international law, by or in relation to–
(a)a third country vessel;
(b)a warship, naval auxiliary, other vessel or aircraft owned or operated by a State and used, for the time being, only on government non-commercial service (whether or not the warship, naval auxiliary or other vessel is a third country vessel).
(2) In paragraph (1), “third country vessel” means a vessel which—
(a)is flying the flag of, or is registered in, any State or territory (other than Gibraltar) which is not a member State; and
(b)is not registered in a member State.