=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Jun-1991
Ko Taphao Noi       545/001 RLR(1981) is 9.8m below BM S.I.
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 12-Jul-2011
While checking datum and benchmark information prior to the uploading of the RLR diagram onto the website the following information was discovered. From 1987 onwards the benchmark was BM 105 5.429m above the 1940-1987 datum. In 1988 the datum was raised 14mm. BM 105 then became 5.415m above the revised 1988 datum. In 1998 the primary benchmark became AS-1/2531 5.304m relative to the 1988 datum.

