(1)    This section applies where—

(a)    an enforcement officer considers that it would not be reasonably practicable for the officer to exercise a power which the officer wishes to exercise in relation to a vessel or marine installation without detaining the vessel or marine installation in a port, or

(b)    an enforcement officer reasonably believes that—

(i)    a vessel or marine installation is itself evidence of the commission of a relevant offence, and

(ii)    the only reasonably practicable way to preserve that evidence is to detain the vessel or marine installation in a port.

(2)    The officer may—

(a)    take, or arrange for another person to take, the vessel or marine installation and its crew to the port which appears to the officer to be the nearest convenient port, or

(b)    require the person who is for the time being in charge of the vessel or marine installation to take it and its crew to that port.

(3)    When the vessel or marine installation has been taken to a port, the officer may—

(a)    detain it there, or

(b)    require the person for the time being in charge of it to do so.

(4)    An enforcement officer who detains any vessel or marine installation under this section must serve a notice on the person who is for the time being in charge of it.

(5)    The notice must state that the vessel or marine installation is to be detained until the notice is withdrawn.

(6)    A notice served under subsection (4) may be withdrawn by service of a further notice signed by an appropriate enforcement officer.

(7)    In subsection (6) the reference to an appropriate enforcement officer is a reference to any enforcement officer acting on behalf of the same relevant authority as the enforcement officer who served the notice under subsection (4), and includes a reference to that officer.

“Relevant authority” means the person or body on whose behalf the officer who detained the vessel or marine installation was acting.