=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Jun-1991 Kiptopeke Beach 960/083 RLR(1973) is 9.8m below BM1 =========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Aug-2011 Using the data from NOAA the RLR diagram has been re-drawn. Primary benchmark L 418 1963 with a value if 4.093m above gauge datum for Epoch 1983-2001. Previous Epoch 1960-1978 value 4.094m. The benchmark originally used by PSMSL BM1 4.328m above gauge datum no longer appears within the NOAA data.