Design and Construction
LM Glasfiber A/S built the LM 23 with a solid fiberglass hull and a long-keel configuration. Its length-to-beam ratio of 2.92 and displacement-length ratio of 280 describe a short, beamy boat with moderate heft for its size. Displacement is 4,409 pounds, including 1,764 pounds of iron ballast, for a 36 percent ballast ratio. Together, those figures suggest a steady, rooted feel rather than the quick reactions of a lightweight racer.
Draft varies from 2.30 to 2.60 feet depending on load. The boat’s immersion rate is about 572 pounds per inch, so it sits heavily and changes trim slowly as fuel and stores come aboard. Wetted surface is roughly 161 square feet, while theoretical hull speed is near 6.1 knots. These figures frame the LM 23 as a boat intended for economical passagemaking rather than speed.
Rig, Engine, and Handling
The masthead sloop rig has a sail-area-displacement ratio of 13.02. That modest figure places the LM 23 firmly in motorsailer territory, where the engine—not the sails—does much of the steady work.
The recommended running rigging uses a uniform 3/8-inch diameter:
- Jib and genoa sheets: 23.4 feet
- Mainsheet: 58.4 feet
- Spinnaker sheets: 51.4 feet
Under diesel power, the LM 23 reaches a maximum of 6.0 knots, essentially matching its displacement hull speed. It has shaft-drive transmission, with an optional 20-horsepower Bukh inboard.
A capsize screening value of 1.84 and a motion comfort ratio ranging from 23.8 to 24.8 suggest a stable platform with a low tendency to tip, favoring predictable motion over athletic performance.
Accommodations
Below, the LM 23 has a single cabin with two berths, a galley, a toilet facility, and a modest 15-liter fresh-water capacity. Mahogany finishes the interior, in keeping with period Danish practice.
The two-berth, single-cabin layout and limited water supply make this a boat for a couple or short-handed coastal cruising. Its motorsailer design trades expansive living space for simplicity and self-sufficiency within a small footprint.
Verdict
The LM 23 is a tidy example of the late-1960s Scandinavian motorsailer: a fiberglass, long-keel design by Palle Mortensen, modestly canvased but sturdily ballasted, with a shaft-driven diesel option and a straightforward small-boat interior. It won’t win light-air races, but its stability figures and immersion behavior point to a predictable, forgiving coastal cruiser.
Pros
- Long keel and 36 percent ballast ratio provide directional stability
- Solid fiberglass hull from an established Danish builder
- Mahogany interior with a galley and enclosed head in a 23-foot footprint
Cons
- Two berths and only 15 liters of water limit extended cruising
- Low sail-area-displacement ratio makes the boat reliant on its engine in light winds
- Shallow, load-dependent draft limits deep-water capability
