The Mk III bears Bill Lapworth’s signature: a spade rudder set well aft, a moderate forefoot flowing into a large fin keel, and a solid-glass hull. At 17,000 pounds, it has a displacement/length ratio of 257. In the words of period reviews, it was a genuine performance cruiser before the type had a name.
Design and Construction
The Mk III’s exterior is restrained and purposeful. Its sheerline is subtle but handsome, the coachroof follows the deck curve naturally, and the freeboard is moderate—low by modern standards. There’s a fair amount of overhang forward and a rakish reverse transom aft.
Below the waterline, the moderate forefoot runs into a large fin keel. Buyers could choose between a standard deep-draft keel drawing 6 feet 8 inches and a shoal-draft model drawing 5 feet 6 inches. The spade rudder, a Lapworth hallmark, sits well aft and has a foam core covered by a thin glass skin.
The hull is solid glass, laid up fairly robustly, with lead ballast. Most of the deck is balsa-cored, with plywood in high-load areas. The hull-to-deck joint uses a conventional inward-facing flange that is both chemically and mechanically fastened. Interior bulkheads are securely tabbed to the hull, while a molded liner forms the cabin sides and overhead.
The finish is better than many sailors might expect from a boat of this era, with excellent joinerwork and teak trim throughout.
Rig and Sailing Characteristics
Two rigs were offered. The standard version has a beefy, keel-stepped, single-spreader spar and a 55-foot air draft. An optional tall rig adds a few feet of mast height and about 50 square feet of sail area. An inner deck track allows close sheeting angles.
With a sail-area/displacement ratio of 16.2, the Cal 39 Mk III is close-winded by cruising standards. Its narrow hull heels early, then stiffens, and the powerful hull shape carries sail in a blow. Owners report that the boat needs a bit of breeze to get moving but then shows a good turn of speed and a seakindly motion.
It can roll when running before a following sea, yet it has enough oomph to surf when conditions allow. The rudder’s aft position provides excellent steering control when running in big seas.
Cockpit and Accommodations
The Cal 39 was one of the first aft-cockpit models to include an aft cabin. In the Mk III, that cabin gained a sink and a large hanging locker. The port cabin is small, but having two private staterooms was a real attraction.
Below, the cabin is fairly bright, with two or three large overhead hatches and eight portlights, most of which open. The finish includes teak trim and notably good joinerwork.
The standard layout places an L-shaped galley opposite the aft cabin—or, on the Mk II, opposite the large quarterberth. The galley usually includes a three-burner stove and oven, large forward-facing double sinks, and a good 8-cubic-foot icebox.
In the saloon, there’s a settee and table to port and a sea-berth settee to starboard. A portside navigation station has a decent chart table, though some models replaced it with an enclosed aft head. Tankage takes up much of the storage beneath the settees.
Forward, the owner’s cabin includes an ensuite head, a hanging locker, and a large V-berth. It can also be reached directly from the saloon.
Machinery and Ownership
Early Cal 39s came standard with the Perkins 4108 diesel, a reliable and easy-to-service engine with available parts. Later boats received either a four-cylinder Universal or, in some cases, a Pathfinder marinized from a Volkswagen Rabbit. Owners complain about the Pathfinder almost without exception, and some boats have since been repowered with Yanmars.
Engine access is poor and available only from behind the companionway. Many Cal 39s entered charter service, while many others have been retrofitted as serious cruisers. The type is an ideal candidate for long-range cruising.
Known Issues
The original teak-and-holly cabin sole isn’t well supported and may require work. Many boats have plastic portlights, so broken dogs and cracked frames warrant caution.
Some owners have reported deck delamination and leaking hull-to-deck joints. The foam-cored rudder can also be troublesome and should be examined carefully during a survey.
The teak toerail looks handsome but is difficult to maintain, especially because the outer headsail track is mounted on top of it. The nonskid is also likely to be well worn by now.
The Verdict
The Cal 39 Mk III is a thoughtful evolution of Lapworth’s performance-cruiser philosophy. Its solid-glass hull and well-aft rudder provide excellent steering off the wind, while the bright, pioneering aft-cabin layout offers two private staterooms. The rig and hull have enough power to carry cruising stores without spoiling the boat’s turn of speed.
Its drawbacks are practical and survivable: substantial keel draft, owner-reported deck delamination and joint leaks, a potentially troublesome rudder core, and punishing engine access. These issues are well understood by a knowledgeable owner base.
Pros
- Pioneering aft-cabin, aft-cockpit layout with two private staterooms
- Bright, well-trimmed interior with excellent joinerwork
- Well-aft spade rudder provides excellent control when running in big seas
- Close-winded, able to carry sail in a blow, and capable of surfing when conditions align
- Solid-glass hull, lead ballast, and a mechanically and chemically fastened hull-to-deck joint
Cons
- Standard 6-foot 8-inch keel limits cruising grounds; many prefer the shoal-draft version
- Pathfinder diesel is widely disliked
- Poor engine access from behind the companionway
- Reported deck delamination, leaking joints, rudder-core problems, and worn nonskid
- High-maintenance teak toerail with the headsail track mounted on top
- Poorly supported cabin sole may need work
