Reading nautical charts, symbols, chart correction, and navigational publications.
Chart symbols and representation of direction and distanceChart correctionNavigational publications in common use
3 outcomes for this module
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.
Preview the onboard scenario
You are preparing a real trip and chart symbols and representation of direction and distance changes the decision. Use this module to explain the cue, the risk, and the next safe action before you move on.
You are preparing a real trip and chart symbols and representation of direction and distance changes the decision. Use this module to explain the cue, the risk, and the next safe action before you move on.
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 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) β reference for all chart symbols
Blue = shallow water, White = deeper, Green = drying land
Charts must be kept up to date β 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 β older = higher risk of errors
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 β tide tables, lights, port info, radio (all-in-one)
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....