Chart Correction and Notices to Mariners

Carriage and update duties depend on vessel and operation; for every skipper, using current navigational information is a safety requirement of a defensible plan. UKHO weekly ADMIRALTY Notices to Mariners publish updates to affected ADMIRALTY products, while navigational warnings and local information may require separate checks.

Notices are categorised into several types. Permanent notices describe lasting changes such as new buoys, altered lights, or changed depths. Temporary (T) notices cover changes that will last for a limited time, such as a temporary light on a construction site. Preliminary (P) notices give advance warning of expected changes. T&P notices are marked on charts in pencil so they can be erased when cancelled.

Apply each correction using the instructions for the chart and product in use, insert new information before deleting old information, and record the NM number and year only after checking the work. Temporary and preliminary information must remain visible and traceable until cancelled; electronic products follow their official update and status process rather than paper-chart pen conventions.

A corrected chart can still be incomplete if a new edition, local warning, harbour direction or current navigational warning has not been checked. Record the information currency in the passage appraisal and identify any limitation that changes the route, margin or departure decision.