The farmed area to be marked either with:
(a) Prefered Option

At the corners with posts extending 900 mm above mean high water springs. Such posts to be marked with a St. Andrews cross, each cross arm measuring 900 mm fromtip to tip, minimum width 75 mm.
OR
(b) Deep Water Sites

At each corner, yellow spar buoys with a yellow St. Andrews Cross as a topmark placed at least 900 mm above the buoy, cross arms 900 mm long x 75 mm wide.
Licence holders are advised that buoys may be subject to shifting and vandalism. Consequently, a regular check should be made to ensure that bouys remain on station, in a good state of repair.
NOTE: Sites which are in deep water, or considered for safety reasons, to be a danger to navigation may require to be marked, In addition to (a) or (b), with lights being yellow in colour and flashing once every 4 seconds and visible over an arc of 360° for a distance of at least one mile.