=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Jun-1991
Adak                820/011 RLR(1985) is 12.2m below BM 18
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 12-Jul-1993
Apparent shifts at data gaps in the late 1950s and early 1960s.
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 23-Nov-2011
Using information from the NOAA website the RLR diagram was revised. Primary benchmark is still 18 1957 - named NO 18 1957 on the NOAA website 6.7m above gauge datum.

