Anchor Chain Scope & Length

Professional marine calculator for boat owners and marine engineers.

Dragging anchor at 2 AM because you let out too little rode? Not sure which scope ratio to use for tonight's weather? This app calculates exactly how much chain or rope to deploy for safe anchoring.

SCOPE CALCULATOR - Enter water depth, freeboard height, tide range, and weather conditions. Calculates required anchor rode length for all-chain, chain-and-rope, or all-rope systems. Shows minimum and recommended scope with swing radius.

SCOPE TABLE - Quick reference for depths 5 to 100 feet at scope ratios 3:1, 5:1, 7:1, and 10:1.

ANCHOR GUIDE - Compare Danforth, Plow/CQR, Bruce/Claw, Mushroom, and Navy types with holding power ratings and best bottom type for each.

BEAUFORT SCALE - Wind speed to sea state reference (Force 0-12) with recommended scope ratio for each condition.

Built for sailors, cruisers, and powerboaters. Supports metric and imperial. Works offline. No account or login required.