Part 4: Police Powers Chapter 5: Maritime Enforcement: English and Welsh Offences Section 88: Power to stop, board, divert and detain
This section provides a power to stop and board a ship, and to direct the vessel to be taken to a port in England and Wales, or elsewhere, and detained there, where a law enforcement officer has reasonable grounds to suspect that an offence under the law of England and Wales is being or has been committed on that ship, or that that ship is being used in connection with the commission of an offence under the law of England and Wales.
	It notes that if the enforcement officer is acting on the authority of the Secretary of State, as set out in section 84(3) or 86(1), the officer can require the vessel to be taken to a port in that vessel's flag state or in another country willing to take the vessel. In exercising that power, an enforcement officer has the power to require any member of a vessel’s crew to take action necessary to support their enforcement activity in relation to that power. Written notice must be provided to the master of any vessel detained under this subsection, which must state the ship is to be detained until withdrawn via a further written notice, signed by a constable or a law enforcement officer.