Imagine this
You are preparing a real trip and true bearings and courses changes the decision. Use this module to explain the cue, the risk, and the next safe action before you move on.
6 lesson sections · 18 quiz questions · 10 flashcards
Day Skipper training module 6 of 17
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Position, Course & Speed
True bearings, courses, latitude, longitude, and the knot.
True bearings and coursesStandard navigational terms
3 outcomes for this module
- Explain true bearings, courses, latitude, longitude, and the knot.
- Apply True bearings and courses to a realistic onboard situation.
- Recall the core check: latitude = N/S of Equator (0°–90°).
Preview the onboard scenario
You are preparing a real trip and true bearings and courses changes the decision. Use this module to explain the cue, the risk, and the next safe action before you move on.
6 lesson sections · 18 quiz questions · 10 flashcards
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.
Latitude and Longitude
Position on the Earth's surface is defined using latitude and longitude. Latitude measures north or south of the Equator (0° to 90°N or S). Longitude measures east or west of the Prime Me...
- Latitude = N/S of Equator (0°–90°)
- Longitude = E/W of Greenwich (0°–180°)
True Bearings and Courses
A true bearing is measured clockwise from True North (0°/360°) through East (090°), South (180°), and West (270°). All chart work is done in true bearings initially — compass corrections...
- True bearings: measured clockwise from True North
- Always written as three figures (e.g., 005°, 090°, 180°)
Speed, Distance, and Time
Speed at sea is measured in knots — one knot equals one nautical mile per hour. Distance is measured in nautical miles (M or nm). One nautical mile = 1,852 metres = 1 minute of latitude.
- 1 knot = 1 nautical mile per hour
- 1 nautical mile = 1,852 metres = 1 minute of latitude
Measuring Bearings on the Chart
To measure a bearing on the chart, use a parallel ruler (or Breton plotter). Align the ruler along the line whose bearing you want to measure, then 'walk' it across to the nearest compass...
- Use parallel rulers or plotters to transfer bearings
- Read from the outer (True) ring of the compass rose
Measuring Distance on the Chart
Distance on a nautical chart is measured with dividers and the latitude scale at the side of the chart. One minute of latitude equals one nautical mile, so the latitude scale is the only...
- ALWAYS use the LATITUDE scale (side of chart) for distance
- 1 minute of latitude = 1 nautical mile
Worked DR and EP from Course, Log, and Tide
Worked DR example: at 1000 you fix your position. From 1000 to 1030 you steer 045 degrees true and the log shows 2.5 M through the water. Plot 2.5 M along 045 degrees true from the fix: t...
- DR = course steered and distance through the water.
- Distance = speed x time; 30 minutes is 0.5 hours.
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