The gauge is situated next to the deep draft wharf.
All heights for the Float and stilling well gauge have been referred to the station tide staff zero which is linked to fixed benchmarks.
Tide gauge benchmark (TGBM) description
This is a NOS bench mark stamped "1000 D 1990", set in a concrete pad supporting ten electrical switch panels.It is 180 feet southwest of the wharf face (established 1990).
Quality Assessment by the UH Sea Level Center
Comment: The daily and monthly means do not reveal any reference level shifts or trends upto the end of 1991. Data from Diego Garcia-B and Diego Garcia-D are maintained in separate records because these series are not linked to the same tide staff zero. Timing errors are evident in the hourly data.