Design Brief & Intent
The Claymore 30 was conceived to bridge the gap between traditional Scottish motorized fishing vessels and modern cruising yachts. Alan Hill’s primary design objective was to maximize accommodation and safety within a compact thirty-foot footprint. To achieve this, the boat features a central cockpit layout that places the helmsman and crew in a secure, high-walled cockpit midships, offering superior protection compared to exposed aft-cockpit designs of the same era.
The interior of the Claymore 30 is characterized by a remarkable amount of usable space and headroom, which was highly unusual for a 30-foot vessel in the late 1960s. The joinery is typical of British semi-custom builds of the period, utilizing robust teak veneers, solid wood trim, and a functional, no-nonsense layout. Because Marcon offered the boat both as a fully finished vessel and in kit form for home completion, the quality of the interior fit-out can vary slightly depending on the skill of the original owner-builder. However, the underlying structural bulkheads and fiberglass moldings remain incredibly robust. The layout is split, utilizing the center cockpit to separate the main saloon and forward V-berth from a surprisingly spacious aft cabin. This configuration provides excellent privacy for cruising couples with guests or children, effectively giving the boat two distinct living zones.
Variations & Configurations
While the baseline Claymore 30 is a full-keeled, masthead sloop with a center cockpit, Marcon and subsequent owners adapted the platform into several distinct configurations. The most common layout features the split cabin configuration: a forward cabin with a V-berth, a central saloon with a linear galley and convertible settee, and the dedicated twin-berth aft cabin. However, a less common aft-cockpit version was also produced, which traded the aft cabin for a more conventional, open cockpit and a single, continuous interior cabin house.
Under the rig, the standard masthead sloop configuration features a robust, tabernacle-mounted mast, which allows the rig to be lowered for navigating inland waterways and canals. A handful of vessels were rigged as ketches to further divide the sail area for easier handling shorthanded, though this added complexity and rigging clutter to a relatively short deck plan. Draft options are uniform, featuring a deep-sided but shallow-draft full keel drawing just over four feet, allowing the boat to slip into shallow drying harbors and navigate European canal networks with ease. Propulsion was anchored around the reliable 36-horsepower Perkins diesel engine, though some late-production models or subsequent refits utilized heavier Ford or Thornycroft diesels to push the heavy hull through stubborn headwinds.
Sailing Performance & Handling
True to its motorsailer designation, the Claymore 30 is not a boat designed to win light-wind club races. With a massive displacement of 12,600 pounds on a 24-foot waterline, the boat has an extremely high displacement-to-length ratio of 406.9, placing it squarely in the ultra-heavy displacement category. This mass, combined with a modest sail plan, yields a conservative sail area-to-displacement ratio of 13.59. In winds under ten knots, the boat is underpowered and sluggish under sail alone, requiring the support of its diesel engine to make reasonable headway.
However, when the wind rises, the Claymore 30 transforms. Its high ballast-to-displacement ratio of nearly 40 percent, supported by 5,000 pounds of encapsulated iron ballast, makes the boat incredibly stiff and stable. It handles heavy weather with a calm, reassuring motion. The hull’s comfort ratio of 35.14 indicates a slow, easy motion in a seaway, reducing crew fatigue during long, rough passages. With a capsize screening formula of 1.72, the design possesses excellent ultimate stability and righting capability. Under power, the hull easily runs up to its theoretical hull speed of 6.5 knots. The full keel tracks exceptionally well in a straight line, though the massive deadwood in front of the rudder means that maneuvering in tight marina slips under power requires deliberate planning and a firm hand on the wheel.
Market Snapshot & Economics
Decades after production ceased in 1980, the Claymore 30 remains a niche but highly respected option on the European brokerage market, particularly in the United Kingdom, Ireland, and Scandinavia. Because of their heavy-duty fiberglass layups and the timeless appeal of the protected center cockpit, these boats hold their value remarkably well relative to light-displacement production boats of the same era.
Prospective buyers should anticipate that a significant portion of any purchase budget will eventually go toward updating the boat's auxiliary systems. Many Claymore 30s still retain their original Perkins engines, which, while famously durable, are approaching the end of their serviceable lifespans and may require complete overhauls or costly replacements. The economics of buying a Claymore 30 are highly favorable for liveaboard couples or long-distance coastal cruisers looking for maximum volume and safety on a modest budget, provided they are willing to invest in updating older electronics, plumbing, and standing rigging.
Known Issues & Triage
While the structural integrity of the solid fiberglass hull is rarely in question, the Claymore 30 is subject to several age-related issues common to Marcon builds of this era.
- Osmotic Blistering: Early British fiberglass layup techniques were highly susceptible to osmosis. While rarely a structural threat on hulls of this thickness, buyers should inspect the underwater profile for blistering. If present, a full gelcoat peel and epoxy barrier coat treatment may be required.
- Deck Core Wetness: Unlike the solid hull, the decks and coachroof of the Claymore 30 are typically constructed with a plywood or balsa core. Over decades, water ingress around leaking stanchions, handrails, cleats, and the mast step can lead to localized delamination and soft spots. Any spongy areas on deck will require cutting away the fiberglass skin, replacing the rotted core material, and re-glassing the area.
- Rudder and Deadwood Drag: The steering on some original models can feel heavy and unresponsive, particularly when sailing off the wind with a quartering sea. This is due to the flat, unprofiled trailing edge of the deadwood and a relatively small rudder area. Many owners have mitigated this by slightly profiling the trailing edge of the keel deadwood and rebuilding the rudder with a more hydrodynamic foil shape to improve steering authority.
Modernization & Upgrades
For owners looking to keep these classic motorsailers viable for modern cruising, several standard upgrades are common. Given the underpowered sail plan, some veteran owners have added a short bowsprit to fly a cruising chute or code zero, significantly improving light-wind sailing performance without compromising the boat's stiff, safe behavior in a blow.
Engine modernizations are also common. While the original Perkins 4.107 or 4.108 diesels are legendary, replacing them with modern, lighter, and quieter 30-to-40 horsepower diesel engines improves fuel efficiency, reduces vibration, and provides more reliable charging capacity for modern house batteries. Due to the generous engine compartment volume and the displacement of the hull, some owners have successfully explored electric conversion projects, though the boat's heavy weight means that a large battery bank is required to achieve practical range under power. Replacing old, deteriorated copper water pipes with modern PEX piping and updating the simple 12V electrical systems with modern marine-grade wiring and lithium battery systems are also highly recommended to support modern liveaboard demands.
The Verdict
The Claymore 30 is an exceptionally robust, safe, and comfortable motorsailer that punches far above its weight class in terms of interior accommodation and heavy-weather sea-keeping. It is a vessel designed for the practical cruiser who values staying warm, dry, and safe over the thrill of high-performance sailing. While it requires mechanical assistance in light air and demands modern upkeep, its solid construction and clever layout make it an enduring classic for coastal exploration and liveaboard voyaging.
- Immense interior volume and headroom for a 30-foot boat, featuring a highly private split-cabin layout.
- Heavily built, over-engineered solid GRP hull designed to handle severe weather.
- Stiff and stable hull form with high comfort and motion ratios, offering a dry and reassuring ride.
- Protected center cockpit design provides excellent safety and shelter from spray and wind.
- Shallow draft and tabernacle mast make it ideal for European canals, estuaries, and shallow harbors.
Cons:
- Underpowered sail plan with a very low sail area-to-displacement ratio, requiring frequent motoring in light wind.
- Sluggish maneuvering in tight marina spaces under power due to full keel and massive deadwood.
- Age-related vulnerability to osmotic blistering and wet deck cores around deck fittings.
- Potential for inconsistent interior finish quality on amateur, kit-built examples.
