=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Jun-1991
Balboa              840/011 RLR(1964) is 13.0m below PBM45
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 03-Jul-1991
Record 1971-1985 from TOGA sea level centre. They take as continuous for time series work having assumed data measured to the tide staff zero throughout. Panama Canal Commission maintain the gauge.
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 05-May-1994
1987-89 datum anomaly queried but no records available to check with
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 12-Jul-1994
1987-89 anomaly may be La Nina related - see Quepos record also.
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 08-Sep-1995
The sea level difference either side of the Panama Canal is approx. 20 cm (higher on the Pacific side) - see for example, Pugh, D.T. 1987, "Tides, surges and mean sea-level", Wiley.
RLR 1964 datum at Balboa is 3.112 m below the "Tide Staff Zero" which is itself 12 feet below Panama Canal Precise Level Datum (PLD). On the Atlantic side, at Coco Solo RLR 1993 is 6.288 m below the Tide Staff Zero which is itself 2 feet below PLD there. For the older Cristobal data, RLR 1964 is 6.138 m below the Tide Staff Zero which is itself 2 feet below PLD.
From inspection of RLR data and from this information, one can indeed verify that sea level is higher on the Pacific side by about 20 cm. However, the accuracy of the PLD national levelling system is unclear.