Port of Rotterdam Authority abandons Normal Amsterdam Water Level after 200 years

The Normal Amsterdam Water Level (NAP) has been used as the basis for Vessel Traffic Services in the port of Rotterdam for some 200 years, according to the company's release. On 1 July, the Port of Rotterdam Authority will abandon NAP in shipping communication. As from that day, it will use the Approximate Lowest Astronomical Tide (ALAT) as a reference for water depths and water levels in the admission policy. Internationally, this reference is common practice in shipping.

LAT is the lowest tide level forecast under astronomic conditions. The new reference came about in collaboration with the Directorate-General for Public Works and Water Management (Rijkswaterstaat) and the Hydrographic Office. The port joins the users of this international language for water depths and water levels, with more efficiency and safety as a result. For the time being, the water depths and levels will be indicated in both ALAT and NAP in the various documents issued by the Port of Rotterdam Authority.