The data used for the construction of sea-level curves in north-western Europe are similar, but interpretations of these data differ. The results show the restoration of sea-level during the Holocene either as an exponential curve or as a curve with marked oscillations. The criteria used to establish the sea-level curve in west Lancashire, England, are described. A core from Downholland Moss, Lancashire, shows that the marine transgressions and regressions recorded there may be the result of a changing sea-level as one interpretation of the data. Index points on some other sea-level curves are briefly examined and tested against the criteria enunciated earlier.