Selecting the correct anchor is arguably the single most important decision for boating safety outside of hull integrity. An anchor is your primary means of stopping and holding your vessel against wind, tide, and current. But with so many shapes and sizes available, how do you choose the right one?

This guide breaks down the most common anchor types and the critical factors you need to consider to ensure you’re securely held, every time.

The Four Main Anchor Types

Different anchors are designed to perform optimally in specific seabed conditions. A good primary anchor should be versatile, but understanding the differences is key.

1. Fluke Anchors (Danforth/Lightweight)

• Design: Features a long, weighted shank and two large, flat, hinged flukes.
• Best For: Soft seabeds, primarily mud and sand. The wide flukes dig deep into these soft materials, creating excellent holding power.
• Considerations: They perform poorly in rock, gravel, or thick grass, as the hinged design struggles to set and can drag across the surface.

2. Claw Anchors (Bruce)

• Design: Recognizable by its three-pronged, claw-like structure.
• Best For: Versatile, good all-rounder for mud, sand, and rock. They are known for setting quickly, even with minimal scope (rode length).
• Considerations: While versatile, they are not always the deepest setting anchor and may not offer the ultimate holding power in the softest mud or hardest sand compared to specialized designs.

3. Scoop/New Generation Anchors (Rocna, Spade, Vulcan)

• Design: Characterized by a weighted tip (ballast) and a concave, scoop-shaped fluke.
• Best For: Arguably the best modern anchor type for all conditions. They are designed to self-right, dig in immediately, and maintain a superior set in everything from soft mud to hard sand.
• Considerations: Often more expensive and can be larger and bulkier than traditional types. They are highly favoured by cruisers and for primary use.

4. Plough Anchors (CQR, Delta)

• Design: Features a plough-shaped fluke (fixed or hinged) that is effective at digging down and setting in various bottoms. The Delta is a modern, fixed-shank version that offers very good performance.
• Best For: Good all-purpose anchor, particularly effective in rock and heavy weeds where the pointed tip can penetrate.
• Considerations: The hinged CQR type can be slow to set and may pull out and reset when the tide changes.

Three Critical Factors for Anchor Selection

Choosing the right anchor isn’t just about the type; it’s about matching the anchor to your boat and your environment.

1. Bottom Composition (Seabed)

The material beneath your boat is the most critical factor. Your primary anchor should be optimized for the seabed you encounter most often.

Bottom Type	Holding Challenge	Best Anchor Type
Mud	Requires large surface area to prevent sinking.	Fluke, Scoop (Rocna/Spade)
Sand	Ideal holding ground; requires deep penetration.	Scoop (Rocna/Spade), Plough (Delta)
Rock/Coral	Needs a point to catch an edge. Risk of fouling.	Claw (Bruce), Plough (Delta)
Heavy Weed	Needs weight and sharpness to cut through.	Plough (Delta), Scoop (Rocna/Spade)

2. Boat Size and Weight

Anchor manufacturers provide detailed charts based on boat length, weight (displacement), and windage (how much of the boat is exposed to the wind). Never undersize your anchor. If your boat is heavier, has a flybridge, or high freeboard, always choose the anchor size recommended for the next class up.

3. Anchor Rode (Chain vs. Rope)

The anchor itself is only part of the system. The rode (the line connecting the boat to the anchor) is equally important:

• All-Chain Rode: Offers superior weight and strength. The weight helps create a low angle of pull (scope), which is vital for setting the anchor effectively and keeping it set.
• Rope Rode (with chain leader): Lighter and easier to retrieve, but requires a much longer scope ratio (more line out) to ensure the anchor sets correctly.

Our Recommendation for New Zealand Boating

Given the varied conditions found throughout the Hauraki Gulf and coastal NZ, we strongly recommend a modern Scoop/New Generation Anchor (like a Rocna or Spade) as your primary bower anchor. Their immediate setting and holding power provide the highest level of safety and reliability in mixed conditions.

For a secondary/stern anchor, a Claw or Fluke design can serve as a lightweight, functional backup.

Need help calculating the right anchor weight and size for your vessel? Visit our store nationwide and talk to one of our marine experts today!