Mark 23 Information, Review, Specs

Sailing Performance & Handling

The Mark 23 is defined by its light-displacement characteristics, featuring a Displacement-to-Length (D/L) ratio of approximately 166. This figure places the boat firmly in the "light racer" category for its era, suggesting a hull that is easily driven and responsive in light-to-moderate air. With a Beam-to-Length ratio of 2.91, the hull offers a relatively narrow entry compared to modern "fat" aft designs, which aids in its ability to track effectively and slice through chop without the excessive pounding common in broader trailer-sailers.

On the water, the boat is known for its agility. Most models were equipped with a retractable swing keel or centerboard, providing a variable draft ranging from 2.17 feet (board up) to 5.08 feet (board down). According to technical data from Sail Dimensions, the Mark 23 utilizes a masthead sloop rig with a generous sail plan for its size. The 3,000-pound displacement provides enough heft to maintain momentum in a sea state, though a Motion Comfort ratio of 14.0 indicates that it remains a lively platform that requires active sail trimming and weight management in heavy gusts.

Interior Comfort & Variations

Despite its performance-oriented hull, the Mark 23 provides a functional interior cabin suitable for weekend cruising. The layout is typical for a 23-foot pocket cruiser of the late 1970s, generally featuring a V-berth forward, a central settee area, and occasionally a small galley station near the companionway. Because of its 7.92-foot beam, the interior feels more intimate than the significantly more voluminous Mark 25, which boasted nearly 5 feet 8 inches of headroom and a much wider 9.25-foot beam.

The Mark 23 was built alongside several siblings under the "Mark" brand, most notably the Mark 25. While the 23 remained a traditional masthead sloop, the larger Mark 25 was often seen with more experimental rigs, including a fractional "V-rig" designed by George Cuthbertson for ease of handling. Buyers of the Mark 23 often preferred its simpler, more conventional rigging and its lighter towing weight, making it a more practical choice for sailors without heavy-duty towing vehicles.

Known Issues & Buyer’s Checklist

Prospective buyers of a Mark 23 should focus on technical areas common to 1970s-era fiberglass builds:

• Keel Pivot and Trunk: The swing-keel mechanism is a high-load area. Inspect the pivot pin for wear and the trunk for signs of stress cracking or water ingress. A "clunking" sound while at anchor or under sail often indicates a worn bushing that requires replacement.
• Deck Core Integrity: Like many production boats of this vintage, the Mark 23 used a balsa or plywood core for deck stiffness. Use a plastic hammer to "tap-test" the deck for dull thuds, which indicate delamination or rot, particularly around the chainplates and stanchion bases.
• Rudder Hardware: The transom-mounted rudder is subject to significant leverage. Check the gudgeons and pintles for play or corrosion.
• Rigging and Spars: Ensure the mast step is not compressing into the cabin top, a common failure point if the internal support post has shifted or decayed.

The Verdict

The Mark 23 remains a hidden gem for sailors who value the design pedigree of John Letcher Jr. and want a boat that sails better than the average "floating caravan" of the same length.

Pros:

• Excellent light-air performance due to low displacement-to-length ratio.
• Deep draft with keel down provides surprisingly good upwind performance.
• Trailerable size allows for expanded cruising grounds and lower storage costs.
• High-quality design pedigree from a respected naval architect.

Cons:

• Relatively light motion comfort makes for a "busy" ride in heavy weather.
• Limited interior headroom compared to more modern, bulbous cruisers.
• Parts and specific manufacturer support are virtually non-existent following the builder's dissolution.