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.

Sheet tension (N)

Tension in the mainsheet.

Boom length (m)

Distance from the gooseneck to the sheet attachment.

Attachment height (m)

Height of the sheet attachment above the gooseneck.

Compute the compression force on the boom from sheet tension via torque balance about the gooseneck. 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]

Boom force (N)

Force acting on the boom at the attachment point.

• 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.

• Air Draft With Heel

  Estimate effective air draft while heeled using a simplified rotation about the lower rail. Actual clearance also depends on hull geometry, trim, waves, and the heel pivot.

• Bowsprit Compression Load

  Compute the ideal axial compression required to balance a forestay load at a specified angle to the deck.

• Jib Halyard Tension Guide

  Guide jib halyard tension using a rule of thumb of eight kilograms force per knot of apparent wind converted to newtons.