surveyed by Lieutenant and Commander H.P. Douglas, R.N., assisted by Lieutenants J.S. Harris. J.S. Schäfer, F.E.B. Haselfoot, and C.H. Knowles, R.N., H.M. Surveying Ship "Waterwitch" 1909, additions in fine line from older surveys ; published at the Admiralty 3rd May 1911 ; Engraved by Dacvies & Company