Use this sailing calculation as a planning or educational cross-check for navigation, wind and current, rig loads, stability, anchoring, tides, visibility, performance, or recovery under explicitly stated conditions.

Shift (°)

Signed wind shift in degrees, positive for a starboard-tack lift.

Determine the favored tack from a signed wind shift where a positive shift lifts the starboard tack and a negative shift lifts the port tack. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Favored tack

The favored tack: port, starboard, or even.

• Actual conditions change with vessel design and loading, sea state, wind, current, tide datum, weather, chart accuracy, equipment, crew, regulations, and safety margins. Simplified formulas do not replace seamanship, approved stability data, or current navigation information.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Cross-check official charts, tide and weather services, instrument data, vessel manuals, and collision regulations; maintain conservative margins and a safe alternative plan.

• Wind Shift Gain Calculator

  Estimate the lateral gain from a persistent wind shift over the distance sailed, with positive lifts gaining and headers losing.

• EP With Leeway

  Estimate the course made good by applying leeway to the true heading, subtracting the leeway angle on the starboard tack and adding it on the port tack.

• Shift Rate Calculator

  Compute the signed rate of the shortest compass-direction change between two mean wind headings, correctly handling the wrap across north.