See unitsNautical publications and chart corrections: almanacs, pilot books, lists of lights and Notices to Mariners
Notices to Mariners and navigational warnings
1The lesson in plain words
Charts and books start to age the day they are printed. Notices to Mariners correct them; radio warnings cover the urgent and the temporary.
Weekly notices
A Notice to Mariners (NM) corrects charts and publications. The UK Hydrographic Office publishes ADMIRALTY Notices to Mariners each week, free to download. The weekly bulletin has sections for chart corrections, navigational warnings in force, and corrections to sailing directions, lists of lights and radio signals. Other offices do the same: the US NGA publishes a weekly NtM, and the IHM a weekly Grupo de Avisos a los Navegantes.
Permanent, temporary, preliminary
Permanent notices give lasting corrections. T&P means temporary and preliminary. Temporary notices describe temporary conditions. Preliminary notices give advance information or report changes before full permanent corrections can be issued; the change may already exist. On paper charts, enter applicable T&P information in pencil. Check that it remains in force and remove or revise it when cancelled or superseded.
Cumulative and annual
The Cumulative List (NP234) lists chart editions and permanent notices within its stated coverage period, not T&P notices. Compare it with your complete chart record; use official archives for earlier notices and check later weekly notices. Check all T&P notices still in force separately. The Annual Summary of Notices to Mariners includes standing notices and a start-of-year T&P snapshot. Check later additions and cancellations too.
Navigational warnings
Urgent information that cannot wait for the weekly notice goes out by radio: a light out, a drifting container, a newly found wreck. The world is divided into 21 NAVAREAs for long-range warnings; Spain coordinates NAVAREA III, the Mediterranean and Black Sea. Coastal warnings go out by NAVTEX and VHF, called radioavisos in Spain. A warning may later become a permanent notice.
Before you sail
Check the latest notices and warnings for your area as part of the passage plan, including T&P notices. A yacht plotter's charts may not show them.
2Key data
- ADMIRALTY NMs
- Weekly, free download; sections for charts and publications
- T&P
- Temporary and Preliminary notices: marked in pencil
- Cumulative list
- NP234: chart editions and permanent notices within its coverage period
- NAVAREA III
- Mediterranean and Black Sea, coordinated by Spain (IHM)
- Spanish terms
- Grupo semanal de Avisos a los Navegantes; radioavisos
3Key points
- 1
Weekly Notices to Mariners correct charts and publications; they are free to download.
- 2
T&P notices are temporary or preliminary and go in pencil.
- 3
NP234 covers permanent notices within its stated period; check all active T&P notices separately.
- 4
Urgent changes can reach you through NAVAREA, NAVTEX and VHF warnings before weekly notices.
4Frequent mistakes
Wrong: A new chart needs no corrections.
Right: Check its edition and recorded correction status. Apply missing permanent corrections and check all T&P notices still in force.
Wrong: T&P notices can be ignored because they are temporary.
Right: They may be the most urgent information you have. Mark them in pencil and check they are still in force.
Wrong: If it is not in the weekly notice, nothing has changed.
Right: Urgent news goes out first by radio warnings. Check NAVTEX and VHF broadcasts too.
5Practice case & exam keys
You bought a chart from a chandler eight months ago and have not corrected it. You plan to sail tomorrow past a harbour where a new breakwater is being built. What do you check?
Show the answer
Confirm the chart edition is current. Compare its complete record with permanent notices, using NP234 within its coverage period, official archives and later weekly notices. Separately check all T&P notices still in force, including older ones. Apply missing permanent corrections in ink and active T&P changes in pencil. Check current navigational warnings too: a change yesterday may not yet be in weekly notices.
Exam keys
- Weekly Notices to Mariners: permanent and T&P corrections.
- T&P notices in pencil; cancelled ones erased.
- NP234: permanent notices within its coverage period; Annual Summary: start-of-year T&P snapshot.
- 21 NAVAREAs; Spain coordinates NAVAREA III; NAVTEX and VHF coastal warnings.
Finish this unit
When you've read it, match the terms, then answer three questions. Get them all right to finish the unit; opening the page alone doesn't count.
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