(1) This Part applies to a ship if:
(a) the ship is in Australia after undertaking a voyage to Australia from a place outside Australia; and
(b) the ship is not a ship that is taken to have been imported into Australia under subsection 49A(7).
(2) This Part applies to an aircraft if:
(a) the aircraft is in Australia after undertaking a flight to Australia from a place outside Australia; and
(b) the aircraft is not an aircraft that is taken to have been imported into Australia under subsection 49A(7).
(3) This Part ceases to apply to a ship when:
(a) the ship has departed from its last port in Australia for a place outside Australia; or
(b) the ship is taken to have been imported into Australia under subsection 49A(7).
(4) This Part ceases to apply to an aircraft when:
(a) the aircraft has departed from its last airport in Australia for a place outside Australia; or
(b) the aircraft is taken to have been imported into Australia under subsection 49A(7).
(5) If:
(a) this Part ceased to apply to a ship because the ship has departed from its last port in Australia as mentioned in paragraph (3)(a); but
(b) the ship returns to Australia before completing a voyage to a place outside Australia;
then, subject to paragraph (1)(b) and subsection (3), this Part applies to the ship after it has so returned as if it has just undertaken a voyage to Australia from a place outside Australia.
(6) If:
(a) this Part ceased to apply to an aircraft because the aircraft has departed from its last airport in Australia as mentioned in paragraph (4)(a); but
(b) the aircraft returns to Australia before completing a flight to a place outside Australia;
then, subject to paragraph (2)(b) and subsection (4), this Part applies to the aircraft after it has been so returned as if it has just undertaken a flight to Australia from a place outside Australia.