=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Jun-1991 Port Orford 823/020 RLR(1986) is 11.0m below BM 6 1937 =========================== FOLLOWING PSMSL DOCUMENTATION ADDED 21-Dec-2011 Using NOAA data the RLR diagram has been reviewed. Primary benchmark remains 6 1937 12.256m above gauge datum (TGZ). Benchmark 1 1924 13.027m above TGZ included in the original RLR diagram is mentioned in the NOAA report of 1992 with a value of 13.028m. It is not included in the later NOAA report of 2003.