=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Jun-1991
Apalachicola        940/043 RLR(1973) is 11.0m below BM1
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 29-Jul-1993
Many stations on the Gulf coast have large values for September 1961.
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 20-Dec-2011
Using NOAA data the RLR diagram has been revised. Original RLR diagram had Primary benchmark BM1 5.672m above chart datum. This may correspond to the current Primary benchmark NO 1 1933 14.124 with a value of 5.669m relative to gauge datum as appears in the last two NOAA reports.

