Coastal Skipper revision module 7 of 17

🗺️

Charts & Publications

Reading nautical charts, symbols, chart correction, and navigational publications.

Chart symbols and representation of direction and distanceChart correction from Notices to Mariners

8 guided lessons · 20 practice questions · 14 flashcards

3 outcomes · self-guided revision
  • Explain reading nautical charts, symbols, chart correction, and navigational publications.
  • Apply Chart symbols and representation of direction and distance to a realistic onboard situation.
  • Recall the core check: charts show depths, coastline, marks, hazards.

A self-guided revision companion that explains essential concepts, then helps you practise and test them. It supports—but does not replace—recognised instruction, practical training, assessment or certification. Access is a one-time payment, not a subscription.

More ways to revise

Lesson summaries

Use this module hub to choose the right lesson, then open the dedicated lesson page for the complete explanation, worked examples, FAQs, and practice questions.

Nautical Charts

A nautical chart is the mariner's map of the sea. It shows depths, coastline shape, navigation marks, hazards, and other essential information. Charts are drawn to Mercator projection, wi...

  • Charts show depths, coastline, marks, hazards
  • Mercator projection — True North at top
Read the full lesson: Nautical Charts

Chart Symbols and Abbreviations

Charts use hundreds of standardised symbols defined in INT 1 (also known as Chart 5011 in the UK). Key categories include: depth contours and soundings, rocks and wrecks, buoys and beacon...

  • INT 1 (Chart 5011) — reference for all chart symbols
  • Blue = shallow water, White = deeper, Green = drying land
Read the full lesson: Chart Symbols and Abbreviations

Chart Corrections

Charts must be kept up to date — new hazards, changed buoys, altered depths, and other changes are published in Notices to Mariners (NMs). Professional vessels correct charts weekly using...

  • Notices to Mariners (NMs) publish chart corrections
  • Always check chart edition date — older = higher risk of errors
Read the full lesson: Chart Corrections

Navigational Publications

Several publications supplement charts: the Nautical Almanac (e.g., Reeds or Macmillan's) contains tide tables, tidal stream atlases, port information, light lists, radio information, and...

  • Nautical Almanac — tide tables, lights, port info, radio (all-in-one)
  • Admiralty Sailing Directions (Pilots) — detailed coast/harbour descriptions
Read the full lesson: Navigational Publications

The Compass Rose

Each chart has one or more compass roses printed on it. The outer ring shows True North (aligned with the chart grid). The inner ring shows Magnetic North, offset by the local variation....

  • Outer ring = True North (chart grid)
  • Inner ring = Magnetic North (offset by variation)
Read the full lesson: The Compass Rose

Admiralty Publications (NP Series)

The UK Hydrographic Office (UKHO) publishes a range of essential Admiralty publications, each identified by an NP number. NP5011 (the UK edition of INT1) is the definitive reference for a...

  • NP5011 (INT1) — chart symbols and abbreviations reference
  • NP100 (Mariner's Handbook) — comprehensive navigator's reference
Read the full lesson: Admiralty Publications (NP Series)

Chart Correction and Notices to Mariners

Keeping charts up to date is a legal requirement for commercial vessels and a matter of safety for all mariners. The primary mechanism for chart correction is the weekly edition of Admira...

  • Weekly Admiralty Notices to Mariners (NMs) are the primary source of corrections
  • Permanent corrections are applied in waterproof violet ink
Read the full lesson: Chart Correction and Notices to Mariners

Electronic Charts (ENC) and ECDIS Awareness

Electronic charts come in two main types. Raster Navigational Charts (RNCs) are essentially scanned images of paper charts — they look identical to the paper version but cannot be interro...

  • Raster charts (RNC) — scanned images of paper charts, cannot be queried
  • Vector charts (ENC) — database-driven, can be zoomed, queried, and customised
Read the full lesson: Electronic Charts (ENC) and ECDIS Awareness

Add the complete practice layer

Keep reading the public lesson articles, and add this module's guided flow, quizzes, spaced-repetition flashcards, progress, and mock exams with one payment.