1941-1942 data supplied by B.O.D.C. 1959-1962 data supplied by the National Geographical Institute, France
Documentation added 1991-06-11
Le Havre 190/051 RLR(1977) is 12.7m below BM NGFNPC17
Documentation added 1994-10-21
1991-93 problems with gauge operation, numerous gaps
Documentation added 2012-03-28
Primary benchmark is now IGN N.CP-15 9.767m above Zero Hydrographique.
Documentation added 2014-09-24
Using values from the SONEL website the latitude and longitude for Le Havre has been revised. The data downloaded from SONEL contained a number of additional data points particularly for the 1980's. Because of this the whole dataset has been re-loaded.