(1)Duties which a person performs on a ship engaged—
(a)on a voyage beginning or ending outside the United Kingdom (but excluding any part of it beginning and ending in the United Kingdom), or
(b)on a part beginning or ending outside the United Kingdom of any other voyage,
are treated as performed outside the United Kingdom for the purposes of this Chapter.
(2)Duties which a person performs on a vessel engaged on a voyage not extending to a port outside the United Kingdom are treated for the purposes of this Chapter as performed in the United Kingdom.
(3)For the purposes of subsection (1) the areas designated under section 1(7) of the Continental Shelf Act 1964 (c. 29) are treated as part of the United Kingdom.
(4)Subsection (1) applies despite anything to the contrary in section 40 (duties on board vessel or aircraft).