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.

Course (°)

Course at the time of the man overboard incident.

Calculate the reciprocal of the course at a man-overboard incident as a planning reference for the return leg. The actual Quickstop maneuver and final approach depend on wind, sea room, and the casualty's observed position. 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]

Return course (°)

Return course steering toward the casualty.

• 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.

• Williamson Turn Course

  Calculate the initial sixty-degree heading and final reciprocal course for a Williamson turn. After reaching the initial heading, reverse the rudder and steady on the reciprocal of the original course.

• Jib Car Position Calculator

  Compute a jib-car reference position as a selected percentage of foot length, measured aft of the clew. Final trim still depends on clew height and sheeting geometry.

• MOB Drift Distance

  Estimate the maximum down-drift distance when current and windage act in the same direction. Vector set and wind directions are required for a position estimate.