Design and Construction
Kirby drew the San Juan 24 to the IOR Quarter Ton Rule, and its racing pedigree is clear in the hull. This predominantly fiberglass recreational keelboat has wood trim, a raked stem, and a raised reverse transom. A fixed fin keel and internally mounted, tiller-controlled spade rudder give it the underbody of a dedicated racer rather than a cruiser.
The boat is 24 feet overall, with an 8-foot beam and a displacement of around 3,200 pounds. Its 1,650 pounds of lead ballast produces a ballast-to-displacement ratio near 52 percent, a figure that explains much of its reputation.
Rig, Performance, and Handling
The masthead sloop rig carries a sail plan that rewards careful trim. Owners report that the San Juan 24 is fast and weatherly upwind. Its PHRF racing average handicap is 219, with a recorded high of 231 and a low of 216, placing it firmly among quick quarter-tonners.
The tiller and spade rudder provide precise control in close quarters. As a trailerable boat, the San Juan 24 can also be launched and tuned without requiring a permanent slip.
The main handling caveat appears downwind. Owners report that the boat can be a little squirrelly when sailing dead downwind under spinnaker in heavy air, possibly because of the narrow underbody aft. That same hull shape contributes to the boat’s effectiveness upwind, so the trade-off is inherent in the design.
This isn’t a structural defect but a dynamic characteristic. The stern lacks the beam to settle the boat while broad-reaching at speed, and a helmsman caught unaware may find it twitchy. It’s a manageable trait with practiced spinnaker technique rather than a fault requiring repair.
Accommodations
For a 24-foot racer, the interior is surprisingly social. It provides sleeping accommodation for five, showing Kirby’s ability to fit berths inside an IOR racing shell without compromising the boat’s lines. The wood trim softens the otherwise fiberglass interior and reflects the boat’s early-1970s American building tradition.
The Verdict
The San Juan 24 is a purist’s quarter-tonner: a Kirby-designed IOR racer that sold 1,200 copies and earned the owner-reported title of “most popular quarter tonner ever” through its sailing ability. It’s quick upwind, tidy to trailer, and sleeps five in a package under 30 feet. Its only behavioral quirk is some skittishness downwind in heavy air, stemming from the same narrow stern that helps make it weatherly.
Pros
- Fast and weatherly upwind, according to owner reports
- Bruce Kirby design with IOR Quarter Ton racing pedigree
- 1,200 built; called the most popular quarter-tonner ever by owners
- Trailerable, with sleeping accommodation for five
Cons
- Can be a little squirrelly dead downwind under spinnaker in heavy air
- Narrow underbody aft contributes to downwind twitchiness
