A black buoy is shown on an historic chart at the mouth of channel between the North and South sands (also known as the Fairway Buoy). Admiralty Sailing Directions dating to 1870 note that the bar is '? less than a quarter of a mile across, and the depth over it (always uncertain) varies between 5 and 7 feet at low water spring tides. Within the bar is 15 feet water. The buoys marking the passage across within it are shifted whenever change occurs. All wind between WSW and NNW produce a heavy sea on the bar, and there is a constant ripple or overfall occassioned by the tide falling into the deeper water on eiither side, according as it is ebb or flood. A black bouy marked 'Caernarvon Bar' lies one mile SSE from the fairway?'
Sources include:
Admiralty, 1870, Sailing Directions for the West Coast of England from Milford Haven to the Mull of Galloway including the Isle of Man, pg75
Historic Admiralty Chart 1412-A7, RCAHMW Digital Collections sourced from UK Hydrographic Office (published 1842)
Historic Admiralty Chart 1464-A1, RCAHMW Digital Collections sourced from UK Hydrographic Office (published 1843)
