Boat Anchor Types: A Comprehensive Guide
Anchors are essential for boats, keeping them secure and preventing drifting in wind or current. There are many boat anchor types, each designed with different shapes and mechanisms to suit various vessels and seabeds. This guide covers the main anchor styles — Fluke/Danforth, Grapnel, Plow/CQR/Delta, Bruce/Claw, Rocna, Mantus, Mushroom — their structure, pros and cons, and appropriate use cases, to help you make an informed decision.
The table below summarizes each anchor type's common use-cases: suitable boat size, ideal seabed, relative holding power, and portability.
| Anchor Type | Suitable Boat Size/Use | Best Seabeds | Holding Power | Portability/Storage |
|---|---|---|---|---|
| Fluke (Danforth) | Small boats, tenders, kayaks | Sand, mud | Very high (best in soft ground) | Light, folds/splits for storage |
| Grapnel (Foldable) | Kayaks, dinghies, small boat | Rock, coral, weed | Moderate (hooks well, poor in sand/mud) | Extremely light, collapsible |
| CQR Plow (Hinged) | Medium to large cruiser | Sand, mud, mixed | Moderate | Heavy, bulky, non-folding |
| Delta/Wing Plow | Medium to large cruiser | Most seabeds | High | Heavy, bulky, non-folding |
| Bruce/Claw | Cruising sailboats, powerboats | Sand, mud, rock | Medium-high | Heavy, non-folding |
| Rocna (Spade) | Cruising yachts | All seabeds (incl. grass) | Very high | Heavy, non-folding |
| Mantus (Spade) | Cruising yachts | All seabeds | Very high | Heavy, non-folding |
| Mushroom | Fixed moorings, buoy | Soft mud/silt | Very high (after burial) | Very heavy, not portable |
Fluke (Danforth) Anchors
Fluke anchors have large flat blades and a high holding-power-to-weight ratio. Designed in the 1940s, Danforth anchors are lightweight and excel in soft bottoms. Once their blades are fully buried in sand or mud, they generate exceptional holding force — ideal for small boats or as backup anchors. The downside is poor performance on hard bottoms like rock, coral, or grass. Easy to stow and carry, fluke anchors are highly effective if your boat often anchors in sandy or muddy spots.
Grapnel Anchors
Grapnel anchors consist of a shank with multiple folding prongs. Extremely popular for kayaks and dinghies, they hook onto hard seabed structures or reefs regardless of orientation — making them the best anchor for kayak fishing on irregular terrain. However, they have little holding power in sand or mud. A folding grapnel is a great choice for small boats in rockier bottoms, but not suitable as a primary anchor in soft conditions.
Plow (CQR/Delta) Anchors
Plow-style anchors include the hinged CQR and fixed-shank Delta designs. Both perform reasonably well across a range of seabeds — sand, mud, gravel — and are a good all-round choice for cruising boats. The Delta typically shows better holding power per pound than the CQR thanks to its larger blade area, though neither excels in hard rock. Plow anchors are heavier and bulky, requiring substantial anchor rollers and deck space.
Bruce/Claw Anchors
The Bruce (claw) anchor, developed in the 1970s, is one of the most popular anchors for recreational boats. Its simple three-claw shape sets easily in sand, mud, rock, and coral, and resets automatically if it breaks loose. The trade-off is somewhat lower holding power per pound than modern designs, so a heavier Bruce may be needed for equivalent holding capacity. Overall, an excellent all-purpose anchor for larger sailboats and powerboats.
Rocna and Mantus Anchors
Rocna and Mantus represent a newer generation of spade-style anchors with roll bars. The Rocna (designed in New Zealand, 2004) features a sharp-spade fluke and roll-bar that causes it to dig in quickly and hold exceptionally well in grass, mud, or sand. Mantus anchors offer similar performance with a broader roll-bar and high-tensile steel shank. Compared to a Delta anchor, the Rocna typically sets faster and digs deeper — making both popular on blue-water cruising yachts, though they tend to be heavier and more expensive.
Mushroom Anchors
Mushroom anchors are permanent anchors used for moorings and fixed stations — not usually carried aboard small craft. Shaped like an upside-down mushroom, they work best in very soft mud or silt. Once deployed, the soil consolidates around them, increasing holding power from roughly 2× to 5–10× the anchor's weight over time. They are extremely heavy and not meant to be moved once set — ideal for mooring channel markers or buoys in silt bottoms.