=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Jun-1991
Dauphin Island      940/037 RLR(1973) is 12.2m 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. Primary benchmark remains BM1 now given the name as appears on the NOAA website NO 1 1960 6.288m above gauge datum.