Anchors and Anchor Gear – A Complete Guide for Boat Owners
An anchor is an essential piece of equipment on any boat. It is practical when you want to stay moored in a natural harbor, and absolutely necessary if something goes wrong. For an anchor to work properly, it must be suitable for both the seabed type and the size of the boat.
See the Marinekauppa anchor selection here
There are several types of anchors, but the most versatile option is the Bruce anchor. Below you will find the differences between the most common anchor types:
Anchor Types
| Anchor Type | Holding Power | Bottom Type | Description |
|---|---|---|---|
| Bruce Anchor | Very good | All-round use | Provides excellent holding on all bottom types, especially sand, mud and silt. If you are unsure which anchor to buy, choose a Bruce anchor. |
| Rocna Anchor | Very good | All-round use | Digs into the bottom and offers outstanding holding power. Excellent for larger boats and long-distance cruising. |
| Delta Anchor | Best | All-round use | Exceptional holding power on all bottoms. Ideal for larger boats and long trips. |
| Fortress Anchor | Good | Sand, silt and mud | A foldable anchor with swiveling flukes. Made of aluminum and very lightweight. Sharp flukes dig deep into the seabed for excellent holding. Durability is comparable to steel anchors. |
| Grapnel Anchor | Weaker | Rocky / hard bottoms | Small and space-saving, but weaker in holding power. Can be difficult to retrieve as it easily gets stuck between rocks. Best suited for small boats on day trips. |
The heavier the anchor, the better it holds. However, heavier anchors are often more expensive and harder to handle than lighter ones. With an electric windlass, even a heavy anchor can be handled safely by one person. The manufacturers recommended maximum boat size refers to the boat weight the anchor should hold in optimal conditions, not in strong winds or storms.
Recommended Anchor Weights
| Boat Weight | Boat Length | Minimum Anchor Weight |
|---|---|---|
| 0–300 kg | Dinghies / inflatables | 3.5 kg |
| 2.0 tons | 7.0 m | 5.0 kg |
| 3.0 tons | 9.0 m | 7.5 kg |
| 4.0 tons | 10.0 m | 10 kg |
| 8.0 tons | 11.0 m | 15 kg |
| 15.0 tons | 12.5 m | 20 kg |
| 20.0 tons | 14.5 m | 30 kg |
Anchor Rode Options
Choosing between chain and lead-weighted rope depends on several factors, such as intended use and personal preference. Below are the characteristics of each option:
Anchor Chain
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Weight and stability: Chain is heavier than rope, providing better stability and helping keep the anchor set.
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Durability: Chain is highly resistant to abrasion, which is particularly useful if the anchor drags across the bottom.
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Less shock loading: Chain absorbs shock from waves and wind better than rope, improving safety and comfort.
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Less drifting: Chain moves less along the bottom, helping the anchor maintain a better hold.
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Less tangling: Chain is far less likely to tangle or knot and can be stored in a smaller locker compared to rope.
Three-Strand Rope
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Lightweight: Lighter than chain, making it ideal for smaller boats where weight matters.
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Affordable: Usually cheaper than chain.
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Quieter: Produces less noise than chain, which is pleasant in crowded anchorages.
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Gentler on the seabed: Causes less damage to sensitive seagrass or coral.
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Can be combined with chain: Often used together with 5 meters of chain for better stability.
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Not recommended overnight: On its own, rope does not provide reliable holding for overnight anchoring.
Lead-Core Rope
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Stable anchoring: The lead core increases weight, helping keep the rope lying flat on the seabed and preventing anchor dragging.
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Fast sinking: Drops quickly to the bottom, improving anchoring efficiency.
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Flexible and easy to handle: Offers the ease of rope with some of the benefits of chain, while remaining lighter to manage.
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Less tangling: Less prone to twisting and tangling compared to standard rope.
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Suitable for overnight anchoring: Provides reliable holding power even for overnight stays.
Maintenance
Both chain and rope should be regularly checked and maintained for safe and reliable anchoring. This includes inspecting chain for corrosion and checking rope for wear to ensure they withstand the stresses of boating.
Anchor Strap Reel
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A practical and space-saving solution.
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Easy to mount on railings, bulkheads, hatches and so on.
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Lightweight.
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Does not tangle: The strap rolls neatly back into the cassette after use.
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The strap absorbs far less water than traditional rope.
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Polyester strap is washable.
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The anchor can remain in place without removing the shackle, as the flat strap allows the hatch to close over it.
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If the reel is not protected from sunlight, the strap should be replaced approximately every five years due to UV degradation.
Recommended Sizes for Rope, Chain and Shackles
Choosing the correct dimensions can be challenging. The table below provides general recommendations based on boat weight. If using a windlass, always confirm that the rope or chain size is compatible with your windlass model.
| Boat Weight | Rope Diameter | Chain Diameter | Shackle Diameter |
|---|---|---|---|
| 0–300 kg | 6–8 mm | 6 mm | 8 mm |
| 2.0 tons | 10 mm | 6 mm | 8 mm |
| 3.5 tons | 12 mm | 8 mm | 10 mm |
| 6.0 tons | 14 mm | 8 mm | 10 mm |
| 10.0 tons | 16 mm | 10 mm | 12 mm |
| 20.0 tons | 18 mm | 10 mm | 12 mm |
Useful Anchor Accessories
Anchor Swivel
An anchor swivel is a rotating connector between the anchor and the chain or rope. It allows 360 degree movement, prevents twisting, and ensures the anchor sets and retrieves correctly.
Anchor Bracket
An anchor bracket is used to securely store the anchor when it is not in use. Brackets come in various styles and can be mounted in different places to keep the deck tidy and the anchor easily accessible.
Anchor Roller
An anchor roller makes lowering and raising the anchor easier. It keeps the anchor aligned, protects the hull and deck from wear, and ensures smooth and efficient anchoring.
