Anchor chain

Model and limitations

SkipperCalc’s indicative all-chain rule uses 4 times total height for a short sheltered stop, 5 for overnight in settled weather and 7 for moderate wind or waves. This is a synthesis of guidance, not a universal table or certified wind thresholds. RYA gives a 4-times maximum-depth reference for chain; Advantage Boating, for a mixed rode, distinguishes overnight (5) and wind/waves (7). We adopt those two factors as indicative allowances in our chain tool, not as that source’s specific all-chain recommendation. We add chain-exit height and round up to a whole metre. We do not calculate a figure for storms or uncertain conditions. Check manufacturer instructions, seabed, anchor holding and swing room.

Check the entire swing area, prohibited zones and protected habitats. RYA — Anchoring with care · Advantage Boating — Anchors and Anchoring