This indicates that the light is a " group occulting light " in which a group of three eclipses repeat every 10 seconds; the light is white; the light is 15 metres above the chart datum and is visible for.
22.
The Groyne shows an occulting light which marks a safe entrance course between the piers, showing white to a vessel approaching from seaward on the correct course, green to a vessel off-course to the north, and red to one off-course to the south.
23.
Like a flashing light, it can be used for a single occulting light that exhibits only a single period of darkness or the periods of darkness can be grouped and repeated at regular intervals ( abbreviated " Oc " ), a group ( Oc ( 3 ) ) or a composite group ( Oc ( 2 + 1 ) ).
