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.

Mast height (m)

Height of the mast above the deck.

Bend percentage (%)

Bend as a percentage of mast height, between 0 and 5.

Compute mast bend from bendMeters = mastHeightMeters * bendPercent / 100. 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]

Mast bend (m)

Lateral bend at the masthead.

• 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.

• Backstay Tension Guide

  Suggest backstay tension from backstayPercent = min(100, max(10, round(apparentWindKt * 4))).

• Ballast Ratio Calculator

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

• Vang Angle Calculator

  Compute the vang angle in degrees as atan of the mast attachment height over the boom attachment distance.