How to check whether the paper sea has expired?
Consult the publication, correction information and expiration time of relevant paper charts. Navigate the network display according to the query. This publication is published annually by the British Naval Hydrographic Office. Nautical notices are an important basis for correcting information, and new trends are updated once a week. The updated version has a clear date, year, month and date. This is the basis for checking whether charts and books are out of date.