This fin-keel monohull displaces roughly 6,800 pounds and carries 3,395 pounds of iron ballast. It belongs to the same design lineage as the larger UFO 34, which Holman & Pye developed from an IOR prototype a few years earlier. However, the UFO 31 is a distinct, slightly smaller cruiser-racer, not a derivative of the later Oyster-associated model.
Design and Construction
The hull and deck are both solid fiberglass. The UFO 31 was also available as a shell for home completion, so finished quality varies from one example to the next.
The boat has an iron keel, and loaded draft ranges from about 5.74 to 6.04 feet, depending on burden. That keeps it within the draft limits of most marina approaches. Beam is just over ten feet, and the length-to-beam ratio is 3.03, giving the boat moderate proportions for a 31-footer.
The ballast ratio is 42 percent. Its published capsize screening figure is 2.02, which means the UFO 31 wouldn’t qualify for ocean racing under that metric. A displacement-length ratio of 198 places it among “moderate racers,” while a motion comfort ratio of 17.5 to 21.0 suggests a settled manner at sea for a boat of this size.
Rig, Performance, and Handling
The UFO 31 carries a masthead rig. The review notes that it has more rig than only 42 percent of comparable sailboats, making it slightly underrigged for its type.
Using the ISO 8666 reference sail, the sail-area-to-displacement ratio is 15.5. It rises to 18.7 with a 135 percent genoa, so reaching performance depends heavily on carrying that larger headsail. The theoretical displacement hull speed is 6.8 knots, and the relative speed performance index is 38.
Rigging dimensions are fully specified. The main, genoa, and spinnaker halyards each measure 90.6 feet at 3/8 inch. Genoa and jib sheets are 30.8 feet at 1/2 inch, while the mainsheet is 77.1 feet at 1/2 inch. These published measurements should simplify planning for rigging renewal.
Wetted surface is about 301 square feet. The immersion rate is 908 pounds per inch, indicating how firmly the boat settles with added load.
Accommodations
No interior arrangement, berth count, or joinery details have been published for the UFO 31. Because some boats were completed at home, cabin plans and finishes may differ from one example to another.
The known external envelope sets the limits for any arrangement: a waterline length of just over 25 feet within a 30-foot-10-inch overall length, a 10-foot beam, and a fin keel.
Buyers comparing the UFO 31 with other boats bearing the UFO name should note that this design comes from Holman & Pye’s mid-1970s work. It isn’t related to the later Italian, Felci-designed UFO sportboats, which share only the name.
The Verdict
The UFO 31 is a modestly powered cruiser-racer with a moderately racing-oriented character, rooted in the British fiberglass boatbuilding tradition of the mid-1970s. Its documented rig dimensions, stability figures, and comfort ratios are useful, but the home-completion option gave the class an uneven finishing pedigree.
It’s best understood as a straightforward, solid-fiberglass Holman & Pye design of its era rather than a bluewater-certified offshore racer.
Pros
- Solid-fiberglass hull and deck molded by Colvic Craft
- Moderate-racer profile with documented stability and comfort ratios
- Draft low enough for most marina access
- Fully specified rigging lengths and diameters, simplifying renewal
Cons
- Slightly underrigged compared with its peers
- Capsize screening figure excludes eligibility for ocean racing under that metric
- Home-completion history means build and finish quality can vary
