=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-JUN-91 :
Ciudad Madero       920/066 RLR(1964) is 9.4m below BM1
=========================== BENCHMARK INFORMATION UPDATE ADDED  12-JUL-93 :
Ciudad Madero       920/066 RLR(1964) is 9.4m below BM1
Ciudad Madero is an historic station last data 1979

