See unitsNautical publications and chart corrections: almanacs, pilot books, lists of lights and Notices to Mariners
Almanacs, pilot books and sailing directions
1The lesson in plain words
Charts show where things are. Almanacs and pilot books tell you how to use a coast: tides, ports, approaches, dangers and local rules.
Two kinds of almanac
A nautical almanac, such as The Nautical Almanac of the UK and US almanac offices, gives the positions of the sun, moon, planets and stars for each hour of the year. You need it for celestial navigation. A yachtsman's almanac, such as Reeds, is a different book: one volume with tide tables, tidal stream diagrams, port information, lights, radio and weather services for a region. It is updated every year.
Sailing directions
Sailing directions, also called pilots, describe the coast for ships: approaches, anchorages, dangers, port facilities, regulations and weather. Official series include ADMIRALTY Sailing Directions (NP numbers), the US NGA Sailing Directions (Pubs 120 to 200, free to download) and, for Spain, the Derroteros of the IHM (Instituto Hidrográfico de la Marina).
Pilot books for yachts
Yacht pilot books or cruising guides are written for small craft. They give harbour plans, depths, berthing, anchorages and photos of entrances. They are often the best guide to a small harbour, but they are private books, so check their edition date and compare with corrected official charts and notices.
Spanish equivalents
In Spain, the Real Instituto y Observatorio de la Armada (ROA) publishes the Almanaque Náutico, the astronomical almanac. The IHM publishes Derroteros (sailing directions), the Libro de Faros y Señales de Niebla (lights and fog signals), the Anuario de Mareas (tide tables) and the Catálogo de Cartas Náuticas (chart and publication catalogue).
Keep them current
Official publications are corrected by Notices to Mariners and replaced by new editions. A yachtsman's almanac needs its free supplements or online updates. Write the date of each update inside the cover, so you know how current it is.
2Key data
- Nautical almanac
- Sun, moon, planets and stars for celestial navigation
- Yachtsman's almanac
- Tides, ports, lights, radio and weather for a region; yearly
- Sailing directions
- ADMIRALTY NP series; NGA Pubs 120–200; IHM Derroteros
- Spanish terms
- Almanaque Náutico (ROA), Derrotero, Catálogo de Cartas (IHM)
3Key points
- 1
A nautical almanac is for celestial navigation; a yachtsman's almanac is a regional handbook.
- 2
Sailing directions describe coasts, ports and dangers for ships; pilot books do the same for yachts.
- 3
Spain: Almanaque Náutico (ROA); Derroteros, Libro de Faros, Anuario de Mareas (IHM).
- 4
Check edition dates and apply corrections and supplements.
4Frequent mistakes
Wrong: The Nautical Almanac contains the tide tables.
Right: It gives celestial data. Tide tables come from tide-table publications or a yachtsman's almanac.
Wrong: A cruising guide replaces the official chart and notices.
Right: It is a private guide. Use it with corrected official charts and the latest notices.
5Practice case & exam keys
Your three-year-old cruising guide shows an entrance through a breakwater. The corrected chart shows it closed. You plan your first visit to this Spanish harbour. What do you do?
Show the answer
Do not use the entrance shown only in the old guide. Check the current IHM Derrotero, notices and official harbour information for the usable approach. Check the guide publisher's updates too. Use the guide for small-craft detail only where it agrees with current sources, then revise your passage plan.
Exam keys
- Nautical almanac: celestial data; yachtsman's almanac: tides, ports, lights, radio, weather.
- Sailing directions (pilots): ADMIRALTY NP, NGA Pubs, IHM Derroteros.
- Pilot books for yachts: harbour plans, anchorages; check the edition.
- Spain: ROA Almanaque Náutico; IHM Derroteros, Libro de Faros, Anuario de Mareas, Catálogo.
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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