Sch 4A para 2
(1) This paragraph applies if a relevant officer has reasonable grounds to suspect that— (a) an offence under section 24B, 25 or 25A of this Act or section 21 of the 2006 Act is being, or has been, committed on the ship, or (b) the ship is otherwise being used in connection with the commission of an offence under any of those sections. (2) The relevant officer may— (a) stop the ship; (b) board the ship; (c) require the ship to be taken to a port in the United Kingdom and detained there. (3) The relevant officer may require the master of the ship, or any member of its crew, to take such action as is necessary for the purposes of sub-paragraph (2)(c). (4) A relevant officer must give notice in writing to the master of any ship detained under this paragraph. (5) The notice must state that the ship is to be detained until the notice is withdrawn by the giving of a further notice in writing signed by a relevant officer.