Design and Construction
Nordcantieri built the Koala 50 as a fiberglass monohull with a solid hull and deck—there’s no core. Beneath the ketch rig, it carries a fin keel, spade rudder, and 14,330 pounds of lead ballast.
The boat measures 15.30 meters overall, with a 40.39-foot waterline and a beam variously given as 4.04 meters and 13.25 feet. Displacement is 36,376 pounds, producing a ballast-displacement ratio of 39.4 percent.
Those figures point to its offshore intent. The Koala 50 has a hull speed near 8.5 knots, a capsize ratio of 1.6, and a comfort ratio above 41, placing it firmly in the offshore-capable band rather than the weekend-bay category. Period reviewers on both sides of the language divide described Clark’s design as a true offshore performance-cruiser, capable—as demonstrated—of taking its owners around the world.
Racing Heritage
The Koala 50 became famous through the CS&RB, which Doi and Franco Malingri modified to compete in the first Whitbread. The modified boat finished eighth in the inaugural Whitbread around-the-world race, a result that anchored the production design’s reputation as more than a comfortable charter hull.
That connection between Clark’s original cruising ketch and its race-proven offshore record isn’t incidental. The same hull form that carried private owners across oceans also carried a stripped and tuned sister ship into the history of global ocean racing.
Rig and Handling
The Koala 50 carries 1,410 square feet of sail against its 36,376-pound displacement. Its sail-area-to-displacement ratio of 20.55 suggests balanced, manageable power rather than overcanvased urgency.
The ketch configuration divides the drive between the main and mizzen. For a boat of this length and ballast profile, that’s a sensible arrangement when sailing shorthanded or trimming for sustained tradewind passages. The fin keel and spade rudder provide the directional control expected of a performance-cruiser, while the 7.05-foot draft keeps the boat within reach of Mediterranean and Aegean anchorages despite the depth of its lead ballast.
Accommodations and Machinery
The Koala 50’s 50.2-foot length and 13.25-foot beam provide enough volume for a three-cabin owner’s layout or alternative configurations. Documented details about the accommodations and layout variations are limited, however, so each hull needs to be considered individually.
Auxiliary power comes from a single 75-horsepower diesel. Together with the solid fiberglass construction, this reflects a boat intended for liveaboard distance cruising rather than seasonal daysailing.
The Verdict
The Koala 50 is a 1973 Robert Clark design that proved itself both as a world-cruising ketch and as the basis for an eighth-place Whitbread finisher. It’s a solid, seaworthy boat with the figures and lineage to support serious passage-making, and its ketch rig remains a practical offshore choice. Individual hulls require inspection for their particular layouts, but the underlying design and its record need no apology.
Pros
- True offshore performance-cruiser capable of circumnavigation
- Solid fiberglass hull and deck with lead ballast
- Ketch rig suited to shorthanded sailing and long passages
- Whitbread racing heritage through the modified CS&RB
Cons
- Limited documented detail about accommodations and layout variations
