=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 03-Jul-1991 RLR(1987) IS 9.5M BELOW BM NO. T 0283 =========================== FOLLOWING PSMSL DOCUMENTATION ADDED 12-Jul-1993 Chendering 550/017 RLR(1987) is 9.5m below BM T 0283 =========================== FOLLOWING PSMSL DOCUMENTATION ADDED 17-Sep-2012 Publication Tidal Observation Records 2010 confirms the Primary benchmark remains BM T0283 4.688m above TGZ.