The buoy is shown warning of the southwestern end of The Row's Rocks. An annotation suggest that a black buoy was susequently replaced by red and white buoy. Sailing Directions dating to 1884 note the complexity of the buoyage system around the Row rocks, the Middle Channel Rock being on the southern edge and notes 'A conical buoy, coloured in red and white horizontal bands and surmounted with a staff and diamond, lies in 7 fathoms westward of the Mid Channel rock and 19 feet shoal...'.

Sources include:
Admiralty; 1884, Sailing Directions for the Bristol Channel, 4th Ed, pg58
Historic Admiralty Chart 2393_A6 RCAHMW digital collections sourced from the UK Hydrographic Office and first published in 1856

Maritime Officer, RCAHMW, August 2014.