Cardinal marks indicate the direction of safety as a cardinal (compass) direction (North, East, South or West) relative to the mark.
The "Fourquies" North cardinal is positioned to the North of the Fourquies reef and indicates to mariners that the danger lies to the South of the buoy. Due to the relatively deep water where the buoy is positioned, mariners should exercise caution in the area as the buoy will move in the tidal stream, particularly at low water. Its position can be seen on the illustration.
The Fourquies Buoy is one of four buoys purchased over twenty years ago from Trinity House. Powered by acetylene gas, they were deemed no longer fit for purpose, but after the Guernsey Harbours maintenance team converted them to solar power they were given a new lease of life.