If the image above appears blurry, or you would like to see a larger image, please view the full-sized image of the RLR diagram.
Add 10.2m to data values up to 1958 to refer to RLR (1960)
Datum line up to 1958 is the same as BM J17 N6 line.
Add 7.137m to data values 1959 onwards to refer to RLR (1960)
RLR (1960) is 10.2m below BM J17 N6