By MAURIPRO Sailing Specialists · Updated June 2026
What Is the Rocna Spade Anchor and How Does It Work?
The Rocna anchor uses a concave spade blade geometry combined with a fixed roll-bar along the crown. When the anchor touches the seabed, the roll-bar prevents it from resting on its side — it always presents the blade at the correct attack angle. As tension builds on the rode, the blade digs progressively deeper, compressing sediment beneath it and generating high holding power relative to its weight. This self-setting mechanism eliminates the need for backing-down multiple times to confirm the anchor is set.
The ROCORG004GS model weighs 9 lb (4.1 kg) and is finished in hot-dip galvanisation, which provides a thicker zinc coating than electroplated alternatives and resists corrosion in saltwater environments over extended seasons. The shank is designed with a forefoot that provides consistent seabed penetration, even in harder substrates like packed sand or clay. This is what sailors searching for a rockna anchor or ronca anchor alternative are often looking for — a geometry-driven design that sets reliably on the first drop.
The Rocna anchor achieves its holding power through a roll-bar self-righting system and a concave spade blade that sets immediately on contact with the seabed.
How to Choose the Right Rocna Anchor Size for Your Sailboat
Rocna publishes sizing recommendations based on boat length and displacement. The 9 lb (4.1 kg) ROCORG004GS is rated for sailboats up to approximately 26 ft in normal conditions, though some sailors on heavier-displacement 28–30 ft vessels use it as a secondary or lunch hook. For primary anchoring, always size up when your boat displacement is above average for its length. Rocna's own guidelines recommend considering wind exposure, rode type (chain vs. rope), and whether you anchor in open roadsteads or protected coves.
The best anchor for your boat is ultimately one that matches your rode system, your bow roller geometry, and your typical anchorage conditions. A heavier Rocna from the galvanised range — the 15 lb (6.8 kg) or 22 lb (10 kg) models — suits Catalina 36 to Catalina 42 sized vessels better for primary use. However, the ROCORG004GS serves excellently as a kedge, stern anchor, or secondary hook on larger boats where stowage space is at a premium.
Rocna Anchor Size Compatibility by Boat Length
| Boat / Application | Boat Length / Displacement | Recommended Rocna Size |
|---|---|---|
| Catalina 22 / Hunter 23 | 22–24 ft / light displacement | 9 lb / 4.1 kg (ROCORG004GS) ✓ |
| Beneteau Oceanis 27 / Jeanneau 279 | 26–28 ft / medium displacement | 9 lb primary or 15 lb recommended |
| Catalina 36 / Hunter 36 | 34–37 ft / ~12,000–14,000 lb | 22 lb (10 kg) recommended |
| Catalina 42 / Island Packet 40 | 40–43 ft / ~18,000–22,000 lb | 33 lb (15 kg) or larger |
For most sailboats 22–26 ft, the 9 lb (4.1 kg) Rocna ROCORG004GS is the correctly sized primary anchor; larger vessels should size up using Rocna's displacement-based chart.
Rocna Anchor Installation: Bow Roller Clearance on a Catalina 42
One of the most common questions MAURIPRO receives from sailors fitting Rocna anchors to their boats concerns bow roller clearance — and this is especially relevant on a Catalina 42. The Catalina 42's factory bow roller is designed with a relatively narrow channel and a fixed pin diameter of approximately 12 mm. The Rocna's roll-bar adds width to the overall anchor profile compared to a traditional plow or CQR anchor, which means the roll-bar may contact the side cheeks of the roller housing before the shank seats correctly.
The recommended solution is to measure the interior width of your bow roller housing and compare it against Rocna's published roll-bar width for the anchor size you are installing. For larger Rocna models (22 lb and up), most Catalina 42 owners report needing to install an aftermarket bow roller extender — such as a stainless steel offshore roller platform — that provides both additional width and forward projection to allow the roll-bar to clear during launch and retrieval. The shank pin hole on Rocna anchors accepts standard 12 mm and 16 mm pins depending on model size, which is compatible with most production bow roller hardware.
For sailors fitting the smaller Rocna Spade Anchor (Galvanised) - 9 lb (4.1 kg) (ROCORG004GS) as a secondary anchor on a Catalina 42, clearance is rarely an issue since the roll-bar dimensions at this weight class are compact enough to fit most standard roller hardware without modification. Always test-fit before committing to a chain-splice or windlass setup.
Rocna anchor installation on a Catalina 42 requires verifying bow roller interior width against the anchor's roll-bar diameter — most primary-sized Rocna models require an aftermarket extended roller platform for proper fitment.
Galvanised vs. Stainless Rocna Anchors: Which Is the Best Anchor Finish?
Rocna offers its anchors in two primary finishes: hot-dip galvanised steel and stainless steel. The galvanised version — like the ROCORG004GS — is the workhorse choice for sailors who anchor frequently and prioritise cost-effectiveness and field repairability. Hot-dip galvanisation deposits a zinc layer typically 85–100 microns thick, significantly heavier than spray-zinc or electroplating. This protects the underlying mild steel from oxidation for multiple seasons of saltwater use, and the finish can be re-galvanised when it eventually wears.
Stainless Rocna anchors use 316L marine-grade stainless steel and are preferred by sailors who prioritise aesthetics and minimal maintenance — particularly for charter vessels or boats stored in the water year-round. The trade-off is cost: stainless Rocna models run approximately 3–4 times the price of their galvanised equivalents at the same weight. For most sailors using the anchor as part of an active cruising setup, the galvanised ROCORG004GS delivers equivalent holding performance at a significantly lower investment. Many experienced bluewater sailors across the anchoras community forums consistently rate the galvanised Rocna as the better value choice for passage-making crews.
The galvanised Rocna anchor provides equivalent holding power to the stainless version at a fraction of the cost, making it the recommended choice for active cruising sailors.
How to Get the Most from Your Rocna Anchor: Rode, Scope, and Set Confirmation
Even the best anchor underperforms when paired with an inadequate rode or insufficient scope. Rocna recommends a minimum of 3:1 scope in calm, protected anchorages and 7:1 or greater in exposed conditions or when forecasting winds above 25 knots. A full chain rode dramatically improves holding by keeping the pull angle low and horizontal against the seabed — which directly feeds the blade-loading mechanism the Rocna's spade geometry depends on. For the 9 lb ROCORG004GS, a 5/16-inch (8 mm) G4 short-link chain is the standard pairing for boats in its target size range.
Set confirmation with a Rocna anchor is straightforward: pay out your full scope, then apply reverse throttle or allow wind to load the rode. A properly set Rocna will show no drag over 30–60 seconds of sustained load. Use a transit — two fixed reference points on shore held in alignment — to confirm the boat is stationary. Because the roll-bar ensures the blade always presents correctly, the Rocna typically sets on the first attempt, which is why it remains a top-ranked choice among sailors comparing rocna anchor options against competing new-generation designs.
MAURIPRO stocks the full Rocna galvanised anchor range, and the Rocna Spade Anchor (Galvanised) - 9 lb (4.1 kg) (ROCORG004GS) is available for immediate dispatch to your dock or delivery address. If you are unsure which size fits your specific boat and rode configuration, contact the MAURIPRO team directly for a personalised sizing recommendation.
Pairing a Rocna anchor with a full chain rode and minimum 7:1 scope in open conditions ensures the spade blade loads correctly and delivers maximum holding power on the first set.
Frequently Asked Questions
What is a Rocna anchor?
The Rocna Spade Anchor (Galvanised) is a roll-bar anchor designed for fast, reliable setting across multiple bottom types including sand, mud, weed, and rock. Its concave blade and weighted tip drive the anchor into the seabed on first contact. MAURIPRO carries the galvanised version, model ROCORG004GS, weighing 9 lb (4.1 kg).
What is the best anchor for a sailboat like the Catalina 42?
The Rocna Spade Anchor (Galvanised) ROCORG004GS is a strong choice for mid-size cruising sailboats. Rocna's roll-bar design self-rights during setting, minimizing dragging risk in variable conditions. For a Catalina 42, verify bow roller compatibility before installation, as Rocna's concave blade geometry requires adequate clearance to seat and deploy correctly.
Is a Rocna anchor the same as a spade anchor?
The Rocna Spade Anchor (Galvanised) ROCORG004GS belongs to the spade-style anchor category, characterized by a concave, shovel-shaped blade that buries deeply under load. Rocna's distinguishing feature is its roll-bar, which prevents the anchor from landing upside-down — a common limitation of traditional spade anchors without this component.
Will a Rocna anchor fit the bow roller on a Catalina 42?
Fitting the Rocna Spade Anchor (Galvanised) ROCORG004GS on a Catalina 42 requires careful bow roller clearance verification. Rocna's roll-bar adds width beyond the blade, and standard factory bow rollers on Catalina 42s may need modification or replacement. MAURIPRO recommends measuring your existing roller opening and comparing it against Rocna's published dimensional specs before ordering.
How much does the Rocna 9 lb galvanised anchor weigh and is it suitable for overnight anchoring?
The Rocna Spade Anchor (Galvanised) ROCORG004GS weighs 9 lb (4.1 kg) and is designed for smaller to mid-size sailboats. For overnight or extended anchoring, Rocna's roll-bar and concave blade provide dependable holding power in sand and mud. Always pair anchor weight selection with manufacturer sizing charts based on your vessel's length and displacement.
Questions? We're Here to Help
Have questions? Chat with us! Our MAURIPRO rigging and sailing specialists are available to help you find the right solution for your boat and sailing style.
Explore our selection: Rocna Spade Anchor (Galvanised) - 9 lb (4.1 kg) (ROCORG004GS) and related sailing gear at MAURIPRO.
