The Secretary of State may by order establish a safety zone around any installation which, or part of which, is stationed in waters to which subsection (7) of section 21 applies, or is being assembled or dismantled in such waters.

The area of a safety zone established by an order under this section shall be defined in the order and may extend outside waters to which subsection (7) of section 21 applies, but shall not extend to any point which would be outside a zone defined in accordance with subsection (5) of that section.

An order under this section may be made in anticipation of an installation’s arriving at its station, so as to come into force when it does so.