M3000-1.4.6.1

Anchor types - advantages and disadvantages

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Candidates most commonly fail this topic by listing anchors they recognise by name without being able to articulate why a Master would choose one over another for a given seabed or operational context. An examiner is not testing catalogue knowledge — they are testing whether you can make and justify a command decision. Generic answers such as "the CQR is good in mud" without explaining the mechanism or the trade-offs will not satisfy at command standard.

The core question the examiner is probing: Can you select the right anchor for the conditions, explain the failure modes, and mitigate them?


Stockless (Admiralty Pattern derivative / Pool-type) The standard commercial and naval anchor. Retracts flush into the hawsepipe, making it practical for large vessels. Good holding in sand and mud once dug in; poor in rock, kelp, or hard clay where the flukes cannot penetrate. Relies on the crown hitting the seabed to trip the flukes. A known failure mode is dragging before it has fully set — critical in restricted anchorages.

CQR (Plough) Hinged plough-blade design. Exceptional in sand, mud, and grass/weed where it self-buries deeply. The hinge allows the anchor to follow changes in load direction without breaking out — a significant advantage on a yacht swinging to tide or wind. Disadvantage: slow to set initially; unreliable on rock or hard sand crust where the plough cannot penetrate.

Bruce / Claw No moving parts; sets quickly and re-sets well if the vessel swings through 360°. Good in sand and mud. Lighter for equivalent holding power compared to CQR. Disadvantage: poor holding in weed or soft mud — the claw tends to skate across the surface. Does not stow as neatly as a plough.

Danforth (Fluke / High-Holding-Power) Exceptionally high holding-to-weight ratio in sand and soft mud — it buries the entire shank. Stows flat. Disadvantage: very poor in rock, gravel, or stiff clay; vulnerable to breaking out if the direction of pull lifts above a low angle; notorious for fouling its own chain over the flukes.

Fisherman (Traditional / Admiralty) The only anchor reliably effective on rock, coral, and kelp because the flukes engage in crevices rather than requiring burial. Holding power-to-weight ratio is low compared to modern designs. Awkward to stow; one fluke always stands proud creating a snagging hazard. A valid choice as a secondary anchor in challenging seabeds where all modern anchors will drag.

Command-level considerations

  • Always assess seabed type from the chart before selecting anchor and scope.
  • Holding power is meaningless without adequate scope; the general principle is a longer scope reduces the angle of pull, keeping the shank horizontal and the flukes buried — exact ratios depend on conditions and anchor type.
  • A second anchor of different type is sound practice where seabed type creates doubt.
  • Monitor set after anchoring: engine ready, transits or GPS alarm set, log the time and position.

Practice questions

recallcore

Name the anchor type most likely to hold effectively on a rocky or coral seabed, and explain why.

recallcore

What is the principal practical advantage of a CQR plough anchor over a Danforth when anchoring on a yacht that may swing significantly to wind and tide?

scenariocore

You are anchoring a 500 GT motor yacht in a bay. The chart shows a mixed seabed of sand patches and weed over rock. You have a CQR on the main bower and a Fisherman as a kedge. How do you proceed and why?

oralstretch

You're telling me a Bruce anchor sets quickly and re-sets well. Under what conditions would you specifically NOT rely on a Bruce as your sole anchor, and what would you do about it?

scenariostretch

A junior officer tells you the Danforth anchor has the best holding-to-weight ratio of any anchor on board — so it should always be the first choice. How do you respond?

Independent preparatory study aligned to the MCA Master (Yachts less than 3000 GT) examination syllabus (updated June 2026). Not an MCA-approved course and confers no credit toward a Certificate of Competency.