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

Elapsed time (s)

Required number in s. Elapsed race time in seconds.

Portsmouth Number

Required number. Portsmouth Number yardstick for the class, typically between 60 and 160.

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

Calculate a Portsmouth Yardstick corrected race time using correctedTimeSeconds = elapsedSeconds * 100 / pyNumber. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Corrected time (s)

Returned number in s. Handicap corrected time in seconds.

• 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.
• 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.

• Reefing Wind Speed Calculator

  Calculate the apparent wind speed at which to reef using reefWindKt = designWindKt * reefFactorPercent / 100.

• Time to Waypoint Calculator

  Calculate sailing time to a waypoint in minutes using timeMinutes = distanceNm / speedKt * 60.

• Ballast Ratio Calculator

  Compute a sailboat's ballast ratio using ballastRatioPercent = ballastWeightPounds / displacementPounds * 100.