How do I choose an appropriately sized stainless-steel anchor for my boat?

Choose a stainless-steel anchor from the manufacturer's sizing chart, using your boat's length and fully loaded displacement, then account for windage and expected conditions. Before buying, check its dimensions against your bow roller, chain connection and windlass, because no anchor suits every boat or holds on every seabed.

Establish weight and anchoring conditions

Start with your boat's loaded displacement. Brochure weight often excludes cruising equipment, water, fuel and stores. A yacht carrying a tender, spare batteries and full tanks can weigh appreciably more than its published light displacement.

Write down these details before comparing anchors:

• Boat make, model, year and length overall.
• Loaded displacement, using a recent weighing figure if available.
• Windage: a flybridge, enclosed cockpit or large deckhouse increases wind load.
• Use: sheltered lunch stops, overnight cruising or exposed anchorages.
• Usual seabed: sand, mud, weed, gravel or rock.

If length and displacement point to different sizes, use the larger recommendation. A light sailing yacht and a tall motor cruiser of equal length need separate assessments.

Check the conditions behind the chart's recommendations. Mantus, for example, distinguishes day anchoring below 30 knots, cruising below 50 knots and storm anchoring above 50 knots. These categories guide selection; they do not guarantee holding in those winds regardless of seabed, scope or setting technique.

Choose design before weight

Equal weight does not mean equal holding power. Fluke area, tip geometry and the ability to bury and reset all affect performance. Choose a design suited to your cruising grounds, then select its size from that model's chart.

Modern scoop designs are commonly chosen for cruising in sand and mud. Plough designs such as the Lewmar Delta remain widely used, while claw anchors have different dimensions and setting characteristics. Weed and rock can defeat otherwise capable anchors, so carrying a second anchor of a different design is useful.

Stainless steel gives a polished finish without a galvanised coating to wear away, but it does not automatically improve holding. Compare the designs themselves before assuming a stainless replacement can be lighter.

If your boat falls near the upper limit of a recommended size, move up a size, particularly for overnight cruising or high windage. Check that your handling arrangements can cope with the extra weight before buying.

Measure the bow roller

A correctly sized anchor can still foul the stem, damage the hull or refuse to launch. Obtain the current dimension drawing for the exact model and weight, as dimensions can change.