🌎️ Mercator Sailing: Course & Distance Calculator

How to Use

Step 1: Enter Departure Position (Position 1)

• Enter the degrees and minutes of latitude and longitude for your departure points.

Step 2: Enter Arrival Position (Position 2)

• Enter the degrees and minutes of latitude and longitude for your arrival point.

Step 3: Calculate

• Click the "Calculate" button to see the results.

Understanding the Results:

• DLAT: Difference in Latitude between Position 1 and Position 2, in nautical miles, with direction (N/S).
• DLO: Difference in Longitude between Position 1 and Position 2, in nautical miles, with direction (E/W).
• MP1: Meridional Parts for the latitude of Position 1.
• MP2: Meridional Parts for the latitude of Position 2.
• DMP: Difference in Meridional Parts between Position 1 and Position 2.
• Quadrantal Course: The course angle (0-90°) measured from North or South towards East or West.
• True Course: The rhumb line course angle (0-360°) measured clockwise from True North.
• Distance: The rhumb line distance between Position 1 and Position 2 in nautical miles.

Important Notes:

• Ensure all coordinate fields (degrees and minutes) are filled correctly.
• The calculator assumes a spherical Earth for meridional parts calculation.
• The DLo calculation finds the shorter arc between longitudes.

Common Uses:

• Calculates the true course to steer and the nautical distance between waypoints.
• Coastal and Ocean passage planning.
• Alternative to Great Circle Sailing.
• Back-up system in case ECDIS fails.
• Naval or sailing school training.