Anchor Types Explained: Danforth, Plow, Mushroom & Grapnel

An anchor holds by either digging into the seabed or, for moorings, by sheer weight. Which mechanism works depends entirely on the bottom: soft sand and mud reward anchors that bury deep; rock and weed reward anchors that hook or grab; permanent moorings in soft ground reward dead weight and suction. Pick the type for your typical bottom first, then size it to the vessel.

The fluke or Danforth-style anchor has two large, flat, pivoting flukes that dig in fast and deliver exceptional holding power for their weight in sand and soft mud. It stows flat, which makes it a popular primary or secondary anchor on smaller boats. The trade-offs: it struggles to set in rock, grass, or hard bottoms, and it can break out and need to re-set if the wind or current swings the boat through a large angle.

Plow-type anchors (CQR and Delta styles) and claw anchors (Bruce style) trade some peak holding for versatility and reliable resetting. A plow digs in like its namesake and resets well when the boat swings, making it a trusted all-round bow anchor across mixed bottoms. The claw sets easily and holds steadily in a wide range of conditions, including some rock and grass, though it gives up holding power per pound to the fluke and plow. Both are favorites on cruising boats that anchor in varied ground.

For permanent moorings rather than day anchoring, holding comes from weight and suction, not a bite. A mushroom anchor settles into soft mud and silt, where it gradually buries and develops strong suction-based hold — ideal for a long-term mooring in a sheltered, soft-bottomed harbor. Deadweight anchors (concrete or cast blocks) hold by mass alone and work on almost any bottom, including hard ground where a mushroom can't bury. Both are sized far heavier than a comparable day anchor because they rely on weight.

The grapnel — a shank with several hooked arms — is built to grab rock, coral edges, and wreckage rather than bury, and folds compact for small craft, kayaks, and as a secondary. It holds poorly in sand or mud, so it is a specialist, not an all-rounder. To choose overall: match the type to your usual bottom (fluke for sand, plow or claw for mixed cruising, mushroom or deadweight for moorings, grapnel for rock), then size to the vessel's displacement and windage and pair it with correctly rated chain and connectors. Many boats carry two complementary types for the bottoms they actually see.