Design and Construction
The Mk III's exterior reads as restrained and purposeful. The sheerline is subtle but handsome, the coachroof flows naturally with the deck curve, and freeboard is moderate—low by modern comparison. There is a fair bit of overhang forward and a rakish reverse transom aft. Below the waterline the moderate forefoot trails into a large fin keel, and two keels were offered: a standard 6-foot 8-inch deep-draft and a 5-foot 6-inch shoal-draft model. The spade rudder is placed well aft, a Lapworth hallmark, and is built of foam with a thin glass skin anchor.
Structurally the hull is solid glass laid up fairly robust, with lead ballast. The deck is balsa-cored in most places but uses plywood in high-load areas, and the hull-to-deck joint is a conventional inward-facing flange both chemically and mechanically fastened anchor. Interior bulkheads are securely tabbed to the hull, and a molded liner forms the cabin sides and overhead. Finish is a cut above what many expect from the era, with excellent joinerwork and teak trim throughout.
Rig and Handling
Two rigs were offered: a standard keel-stepped single-spreader spar with a 55-foot air draft and an optional tall rig that adds a few feet of mast and about 50 square feet of sail area. The single-spreader spar is beefy and keel-stepped, and an inner deck track permits close sheeting angles. With a sail-area/displacement ratio of 16.2 the boat is close winded by cruising standards. The narrow hull heels early and then stiffens up, the powerful shape carries sail in a blow, and owners report she needs a bit of breeze to get moving but then shows a good turn of speed and seakindly motion. She rolls running before a following sea yet has enough oomph to surf when conditions allow, and the aft-placed rudder gives excellent steering control when running in big seas.
Accommodations
This was one of the first aft-cockpit models to carry an aft cabin, and the Mk III refined it with a sink and large hanging locker in that cabin. The port cabin is small, but the two private staterooms were a real attraction. The cabin is fairly bright with two or three large overhead hatches and eight portlights, most opening. The standard plan puts an L-shaped galley opposite the aft cabin or, on the Mk II, the large quarterberth; the galley usually has a three-burner stove and oven, large forward-facing double sinks, and a good 8-cubic-foot icebox. The saloon has a settee and table to port, sea-berth settee to starboard, and a portside nav station with a decent chart table—though some models substituted an enclosed aft head at the nav station's expense. Tanks consume much of the under-settee storage. Forward is the owner's cabin with ensuite head, hanging locker, and large V-berth also reachable from the saloon.
Known Issues
The original teak-and-holly cabin sole is not well supported and may need work. Many boats have plastic portlights, so broken dogs and cracked frames deserve wariness. Some owners have noted deck delamination and leaky hull-to-deck joints, and the foam-cored rudder can be a problem that should be carefully examined during survey. The teak toerail looks great but is a pain to maintain, especially with an outer headsail track mounted atop it, and the nonskid is likely well worn by now.
Refits and Ownership
Early Cal 39s came standard with the Perkins 4108 diesel—a reliable, easy-to-service engine with available parts—while later boats received a four-cylinder Universal or, on some, a Pathfinder marinized from a Volkswagen Rabbit. Almost without fail owners complain about the Pathfinder, and some boats have been repowered with Yanmars. Engine access is poor, only from behind the companionway. Many 39s went into charter service and many more have been retrofit into serious cruisers; the type is an ideal candidate for long-range cruising.
The Verdict
The Cal 39 Mk III is a thoughtfully evolved expression of Lapworth's performance-cruiser philosophy: a solid-glass hull with a well-aft rudder that steers beautifully off the wind, a bright and pioneering aft-cabin layout, and enough rig and hull power to carry stores without sullying the turn of speed. The drawbacks are practical and survivable—keel draft, owner-noted deck and joint leaks, a fragile rudder core, and a punishing engine bay—but they are well understood by a knowledgeable owner base.
Pros
- Pioneering aft-cabin aft-cockpit layout with two private staterooms and a bright, well-trimmed interior
- Well-aft spade rudder delivers excellent control running in big seas
- Close-winded, carries sail in a blow, and surfs when conditions align
- Solid-glass hull, lead ballast, and mechanically plus chemically fastened deck joint
Cons
- Standard 6-foot 8-inch keel limits cruising grounds; shoal draft preferred by many
- Pathfinder diesel widely disliked; engine access poor from behind companionway
- Deck delamination, leaky joints, rudder-core problems, and worn nonskid reported
- Teak toerail with mounted headsail track is high-maintenance; cabin sole may need work
