Anchor Scope Calculator
Calculate anchor rode length (chain plus rope) from water depth and sea conditions.
Returns 5:1 to 10:1 scope ratios for safe anchoring in any conditions.
Rode Required
Anchor Scope Scope = Total Rode Length / Total Rode Depth. Total Rode Depth = Water Depth + Height of Bow Chock above waterline.
Recommended Scope Ratios Calm / Fair weather: 3:1 minimum. Normal conditions: 5:1. Rough / Storm: 7:1. Severe storm: 10:1.
Chain vs Rope Chain is heavier and lies along the seabed, creating a catenary curve that absorbs shock loads and improves holding. At minimum, use 10–15 feet (3–5 m) of chain even on an all-rope rode. An all-chain rode offers the best holding but is much heavier and harder to handle.