Storm Anchors: Building a Second Anchor Setup That Holds

A primary anchor and a good windlass handle the vast majority of anchoring nights. The second anchor exists for the minority of nights that go wrong, and there are more scenarios than most sailors plan for. The obvious one is dragging: a squall comes through, the primary breaks out or skips across a patch of harder bottom, and you need holding power in the water fast while you sort out why the first anchor let go. A second anchor, already rigged and reachable, turns that from an emergency into a procedure.

Less obviously, a second anchor is a tool you use deliberately, not just in a crisis. Tandem anchoring — running two anchors in line to multiply holding power in one direction — is the right answer when a genuine blow is forecast from a known quarter and you want more than one anchor's worth of resistance without over-scoping a single hook. A Bahamian moor, with anchors set roughly opposite each other, trades some ultimate holding power for a dramatically reduced swing circle, which matters in a crowded or narrow anchorage where boats around you are swinging on all-chain rodes of different lengths. And kedging — carrying an anchor out by dinghy to pull a grounded boat free, or to reposition without the engine — is a job only a second, separately deployable anchor can do while the primary stays down.

None of this replaces a properly sized primary. See our best anchors and windlasses guide for choosing that anchor and the ground tackle that runs it. This guide picks up where that one leaves off.

It's tempting to size a second anchor purely by weight, the way manufacturer charts are usually laid out. But holding power in a given bottom is a function of fluke area and geometry as much as mass. A modern concave scoop anchor buries its whole fluke and generates holding power well beyond its weight class in mud and sand. A flat-fluke Danforth-style anchor achieves excellent holding-to-weight in soft bottoms through fluke area and angle, not bulk. An aluminium Fortress-style anchor trades steel's density for a larger fluke at a fraction of the weight, and holds accordingly well in the bottoms it's designed for.

What none of these designs fix is bottom type. A large fluke that's brilliant in soft mud can skate uselessly across hard-packed sand or rock, and a design that sets instantly in sand may struggle to penetrate heavy weed at all. This is the real argument for choosing a second anchor that's genuinely different from your primary, rather than a second copy of it: redundancy across bottom types, not just redundancy of steel in the water.

As a rough sizing starting point — and only a starting point, since manufacturers' own charts vary and should always be your final word — a second/storm anchor is often sized at or slightly above the weight a manufacturer recommends for your boat's length as a primary, on the logic that it may need to hold alone in worse conditions than the primary was ever asked to. A lighter kedge anchor, by contrast, is sized for control and dinghy-handling rather than maximum holding, since its job is repositioning rather than surviving a storm.

Soft mud rewards fluke area over weight — a Danforth-style or aluminium anchor with a wide, thin fluke will often out-hold a heavier, narrower design because it doesn't need to fight its way through resistance to bury. The trade-off is that mud-optimized anchors can be slower to reset if the boat swings through a big wind shift, since they need to break out and re-dig rather than simply rotate.

Thin sand over rock is deceptive and dangerous: an anchor that sets beautifully on the first try may be riding on a thin veneer of sand with almost no real penetration, and a wind shift can pop it straight out onto bare rock. This is a bottom where you want to dive on the anchor if at all possible, or at minimum back down hard and watch for the anchor dragging sideways rather than digging deeper.

Weed defeats most fluke-style anchors outright — the flukes ride up on a mat of grass or kelp roots and never reach the sand beneath. Heavier, sharper, narrower-fluke designs with real point-loading at the tip do better, and sometimes the only real answer is finding a sandy patch between weed beds rather than fighting the bottom you're given.

Coral is its own category and, where it's alive, an ecological one: anchoring on live coral damages a slow-growing habitat and is illegal in many marine parks. Where anchoring on coral rubble or dead coral is unavoidable, expect chain to snag and chafe against rock edges even where the anchor itself holds fine, and rig chafe gear accordingly, as covered in our anchor chain and rode guide.

Catenary — the sag in a chain rode that lets it absorb load by lifting rather than pulling straight — does real work in moderate conditions, but it largely disappears in genuine heavy weather. At 40 knots and above, the wind loads the rode enough to pull most of the chain's belly straight, and the rode behaves much more like a straight-line connection between boat and anchor than the gentle catenary curve you see on a calm night. That's precisely why scope, snubbers, and rode stretch matter more, not less, as the wind builds — catenary can't be relied on to do the shock absorption for you.

Practically, that means going longer on scope than the calm-weather rule of thumb when swing room allows — many experienced cruisers move from the standard 5:1 or 7:1 toward 8:1 or 10:1 as a blow sets in, specifically to keep the angle of pull on the anchor as low as possible and to let the rode itself absorb more of the shock loading through stretch and (what little remains of) catenary. When you're anchoring with two anchors down, remember that scope calculations get more complex — a tandem set effectively shares one rode axis, while a Bahamian moor needs each rode individually assessed for the swing room actually available in each direction.

Any all-chain rode transmits shock loads directly and violently to whatever it's attached to — the anchor, the windlass, the bow roller, the boat's structure. A snubber, a length of stretchy nylon between a chain hook and a deck cleat, exists to interrupt that chain of stiffness with something that can stretch. This matters for a primary anchor and matters even more for a second anchor set specifically because the weather has turned, since that's exactly when shock loads spike.

A single-leg snubber to one cleat is simpler to rig, but a Y-shaped bridle to both bow cleats spreads the load across more of the boat's structure and — just as usefully — reduces the yawing that drives a boat to sail around at anchor, generating its own additional loads on both rodes. In a tandem or Bahamian-moor setup, a bridle on whichever anchor is taking the brunt of the wind is close to essential.

Chafe is the silent failure mode that undoes good ground tackle choices. Every point where line or chain runs over metal or across a hard edge — a bow roller, a fairlead, a chain hook under load — needs inspection and, where the rode is nylon, real chafe protection: leather, hose, or a dedicated chafe guard, checked and adjusted through the worst of a blow, not just rigged once and forgotten. See our anchor chain and rode guide for more on rode construction and chafe management specifically.

The single biggest reason sailors skip a second anchor isn't cost — it's that there's nowhere obvious to put it. A few workable answers, in rough order of how much deck hardware they require: a disassembling aluminium anchor bagged flat in a cockpit locker or lazarette; a stern rail mount, which keeps a full steel anchor ready to deploy without a second bow roller but adds weight aft and a boarding obstruction; a second, offset bow roller sized for a smaller anchor than the primary; or simply lashed stowage on deck against the pulpit, accepting some chafe risk to the gelcoat and rig where the anchor's flukes contact the boat.

Whichever you choose, security in a seaway is non-negotiable — a loose 20-40lb anchor in a knockdown or a hard sea is a genuine hazard to the hull and to crew. And the anchor needs to be reachable and deployable in the conditions you'd actually use it in, not buried under sail bags and fenders that need clearing first. If deploying your second anchor requires a ten-minute locker excavation, it will not get deployed in time when it matters.

For a tandem set or a Bahamian moor, precise placement matters, and a dinghy gives you control that motoring the boat itself can't match. The anchor, enough rode to reach the intended spot plus some slack, and a fender or float to mark the rode's end all need to fit in the dinghy without swamping it — a heavier steel anchor is a genuine two-person job in a small tender, one to row or motor and one to manage the anchor and rode paying out cleanly over the side, not tangled around anyone's ankles.

Pay the rode out from the boat as the dinghy moves away, rather than trying to carry a coiled pile of chain or rope in the dinghy itself, and communicate clearly about when to drop — dropping the anchor at the wrong point defeats the whole purpose of a deliberately placed second hook. Once it's down, back down on it from the primary boat's position to set it properly, exactly as you would a primary anchor.

The critical judgment call is timing: launching a dinghy gets progressively harder, then genuinely dangerous, as wind and sea build. If a blow is forecast and you intend to set a second anchor, do it early, while conditions are still calm enough for safe dinghy work — not after the squall has already arrived and you're trying to launch a tender into breaking chop. For storm sail handling and heavy-weather tactics more broadly, see our storm sails and drogues guide.

There's no single "best" second anchor — the right choice depends on what you're protecting against and what your boat can physically stow. The comparison below is a starting point, not a substitute for the manufacturer's own sizing chart for your specific boat's length, beam, and windage.

Budget tiers

Entry level (roughly $80-$250): a galvanized Danforth-style fluke anchor sized for kedging or light second-anchor duty, plus a basic chain hook. Adequate for mud and sand anchorages and occasional kedging, not a substitute for a properly sized storm anchor on a boat over about 35 feet.

Mid-range (roughly $300-$700): an aluminium Fortress-style anchor or a mid-sized modern steel scoop anchor, a nylon-and-chain rode built for hand deployment, and a real snubber or bridle. This is where most cruising boats land for a genuinely usable second-anchor setup.

Committed bluewater setup (roughly $700-$1,500+): a full-size steel scoop anchor matched to or exceeding the primary's rating, a dedicated stern mount or second bow roller, a purpose-built bridle, and a spare rode long enough for genuine storm scope. Sized for a boat that expects to anchor out in serious, sustained weather rather than mostly marinas and settled coastal stops.