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.

Anchor scope ratio

Ratio of rode paid out to depth; seven to one is standard for overnight anchoring.

Water depth (m)

Water depth at anchor; add freeboard to the charted depth for best accuracy.

Estimate the maximum anchor-to-bow radius from water depth and rode scope. Add the vessel length when checking the full area swept by the stern. 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]

Anchor circle radius (m)

Maximum anchor-to-bow radius; this does not include the vessel length.

• 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.

• Anchor Rode Length Calculator

  Compute the anchor rode length needed from water depth, freeboard, and scope ratio.

• Anchor Scope Ratio Calculator

  Compute the scope ratio from the deployed rode length and the total height to the bow chock.

• Swing Circle Area Calculator

  Calculate the area a boat can sweep as a circle around its anchor from the anchor circle radius.