Use this sailing calculation for planning or education when the vessel, units, reference directions, environmental conditions, and assumptions are explicitly known.

From latitude

Required number.

From longitude

Required number.

To latitude

Required number.

To longitude

Required number.

The cited overview of Navigation supplies background for the terminology and domain context used by this tool.^[1]

Calculate the constant rhumb line bearing from one geographic position to another. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Rhumb bearing

Returned number.

• Vessel design and loading, sea state, wind, current, tide datum, weather, chart accuracy, equipment, crew, and safety margins can make real conditions differ from a simplified result.
• From latitude must be at least -90.
• From latitude must be no greater than 90.
• From longitude must be at least -180.
• From longitude must be no greater than 180.
• Use finite inputs in the displayed units, preserve source measurements and assumptions, and independently verify consequential decisions.

Cross-check current charts, tide and weather services, instrument data, vessel manuals, and applicable navigation rules, and retain a conservative alternative plan.

• Cross Track Error Calculator

  Calculate the signed perpendicular distance from a desired course given distance run and the bearing back to the start point.

• Great Circle Distance Calculator

  Calculate the great circle distance in nautical miles between two geographic positions.

• Lighthouse Geographic Range Calculator

  Compute the geographic range at which a light becomes visible as one point one seven times the sum of the square roots of observer and object heights in feet.