Why Anchor Choice Matters
An anchor that drags while you sleep is a nightmare — and can be a life-threatening emergency if it happens near rocks or a lee shore. Different anchor designs hold differently in mud, sand, rock, and grass. Choosing the right anchor for your primary cruising area and boat size is one of the most important gear decisions you'll make.
Anchor Types
Plow (CQR, Delta)
Classic and proven. Holds well in sand and mud. Self-launches easily. The Delta (fixed shank) is now more popular than the CQR (hinged shank). Good all-around choice for cruising boats. Not great in rock or dense grass.
Fluke (Danforth)
Excellent in sand and soft mud — sets quickly and holds hard. Folds flat for easy storage. Struggles in grass, rock, and heavy clay. The go-to anchor for powerboats in protected anchorages.
Bruce/Claw
Good all-around performance, self-launches from a bow roller, handles changing wind direction well. Never truly excels in any one bottom type but rarely fails either. Popular on liveaboard and cruising sailboats for its reliability.
Rocna / Spade / Mantus (New Generation)
Modern designs with concave blades that set faster and hold harder than traditional anchors. More expensive but outperform traditional designs in almost every test. If you're buying one anchor for serious offshore or extended cruising, a new-generation anchor is worth the premium.
Grapnel
Folding anchor for small boats, dinghies, kayaks. Holds in rocks. Not suitable as a primary anchor for anything larger than a 16-foot runabout.
Sizing Your Anchor
Most manufacturers provide sizing charts by boat length and displacement. A common mistake is under-sizing. In rough conditions, a properly-sized anchor means all the difference.
- Under 20 ft: 7–15 lb
- 20–26 ft: 15–25 lb
- 26–32 ft: 25–35 lb
- 32–40 ft: 35–55 lb
- Over 40 ft: 55+ lb (consult manufacturer)
Go up a size if you anchor in exposed, rough conditions or if your boat has high windage (lots of superstructure, bimini, canvas).
Chain vs. Rope (Rode)
Your anchor rode — the line connecting the anchor to your boat — dramatically affects holding power.
- All-chain rode: Heavy, expensive, no stretch, maximum holding, ideal for cruising and stern-anchoring. Required for long-term anchoring.
- Chain + rope combo: 15–30 ft of chain at the anchor end, then three-strand nylon rope. The chain provides weight (catenary) and abrasion resistance. The nylon absorbs shock. Best for most recreational boaters.
- All-rope: Inexpensive, lightweight. Fine for calm anchorages, but rope alone drags in wind and current without the weight of chain to keep the anchor at a low angle.
Scope
Scope is the ratio of rode length to water depth (measured from the bow roller). More scope = more holding power.
- 7:1 scope — standard minimum in open anchorages
- 5:1 scope — acceptable in calm conditions with all-chain
- 10:1 scope — for storm conditions
Always add the height of your bow roller above the water to the depth when calculating rode length. In 10 ft of water with a 5 ft freeboard, you need 7:1 of (10+5=15 ft) = 105 ft of rode.
Anchor Handling Tips
- Lower, don't throw — throwing tangles the rode and fouls the anchor
- Back down on the anchor at low throttle to set it before trusting it
- Mark your rode every 20 feet (paint, tape, or chain links) so you know how much you've deployed
- Check your anchor set by getting a bearing on two fixed points — if both bearings change, you're dragging
- Use an anchor alarm app on your phone as a backup
A good anchor, properly sized and deployed on adequate scope, will keep you safe and sleeping soundly. Don't skimp on your ground tackle — it's the most important gear on your boat when the engine is off.
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