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

Lateral offset (nm)

Required number in nm. Perpendicular offset to close.

Tack angle (°)

Required number in °. Angle between the tack and the offset direction.

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

Compute the distance sailed on one tack to cover a given lateral offset. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Tack distance (nm)

Returned number in nm. Distance sailed along the tack.

• 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.
• Lateral offset must be at least 0.
• 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.

• Gybe Distance Calculator

  Compute the distance sailed during a gybe to cover a given lateral offset.

• Layline Distance Calculator

  Compute the distance along a layline to the mark given the lateral offset and tack angle.

• Distance to Layline Calculator

  Calculate the distance along the course centerline to a layline from the lateral offset and half of the total angle between port and starboard tacks.