Roughly the size of a Star boat, the Dyas is a round-bilge rundspanter rather than a family cruiser. It has no berths for a full crew. Instead, it’s a light-displacement planing dinghy-keeler designed to be sailed hard by two people, with trapeze and spinnaker at the ready.
Design and Construction
Stöberl designed the Dyas with a fibreglass hull and deck, built as a solid round-bilge form. A fin keel with a bulb carries 573 pounds of lead ballast, while total displacement is about 1,334 pounds. Its ballast-displacement ratio of 42.95 percent puts it ahead of 82 percent of comparable designs in ballast weighting.
A displacement-length ratio of 77 places the Dyas firmly among “ultra light racers”; 93 percent of similar sailboats are heavier. Its narrow proportions are equally striking. The boat measures 23.46 feet overall but just 6.4 feet on the beam, giving it a length-to-beam ratio of 3.68. That makes the hull slimmer than 99 percent of similar designs and helps explain why the original announcement emphasized planing characteristics rather than room below.
Wetted surface is about 150 square feet, and immersion is roughly 441 pounds per inch. As a result, the boat reacts quickly to changes in crew weight and loading.
Rig and Handling
North Sails Wagner developed the fractional sloop rig and supplied the sails before the class received any national recognition. The mainsail and jib provide 195.9 square feet of working sail area. With a 135 percent genoa, the sail-area-to-displacement ratio rises to 29.1, compared with 25.8 using the ISO reference sail.
That powerful rig is deliberate. The Dyas carries more rig than 100 percent of similar sailboats, making it significantly overrigged. Its SA/D figure also indicates that it’s faster in light wind than 96 percent of comparable designs.
Those numbers come with clear limits. A capsize screening value of 2.32 means the Dyas wouldn’t be accepted for ocean races. Its Motion Comfort Ratio of 8.3 makes it more comfortable than only 8 percent of similar designs. This is a stiff, quick and unforgiving racer—not a passage-maker. Its theoretical top speed is near 6 knots.
Accommodations
The Dyas was offered as a two-man regatta boat, and the sources describe no cruising interior, galley or head. Its Star-boat-scale dimensions and round-bilge hull serve the racing rule and the trapeze crew, not life below deck.
Anyone looking for a weekender will find the answer in the boat’s category: the Dyas is a two-person racing keelboat, originally offered regatta-ready with a spinnaker and trapeze.
The Verdict
The Dyas is a pure expression of late-1960s German one-design racing thought: a bulb-finned, round-bilge fibreglass keelboat with extreme slenderness, ultra-light displacement and a rig deliberately sized for speed and planing. Stöberl’s lines and North Sails Wagner’s rig gave it light-air performance that almost nothing in its size class could match.
The same figures that make the Dyas quick also make it tender by offshore standards and sparse by cruising ones. For two-person racing, it remains a distinctive, well-ballasted little keelboat. For anyone seeking a cruiser or passage-maker, it’s the wrong tool.
Pros
- Slender hull and ultra-light displacement put it among the fastest light-air designs in its class
- High ballast ratio and bulb fin keel provide stiffness and bite for a 23-footer
- Purpose-built fractional rig developed by North Sails Wagner and supplied with class sails
Cons
- Capsize screening value excludes it from ocean racing
- Motion Comfort Ratio trails 92 percent of similar designs
- No cruising accommodation; conceived strictly as a two-person regatta boat
