Design and Construction
The Inferno 31 has a solid-fiberglass hull and deck, along with a lead fin keel. It carries 2,204 pounds of lead within a displacement of 9,479 pounds, giving it a 44 percent ballast ratio.
The hull has a 9.84-foot beam and a 25.6-foot waterline. Its length-to-beam ratio is 3.15, while its displacement-to-length ratio of 253 places it among moderate racers. Wetted surface is about 290 square feet, and the immersion rate is 877 pounds per inch.
The boat’s capsize screening value is 1.86, and its Motion Comfort Ratio is 25.4.
Rig and Sail Plan
The fractional sloop rig produces a sail-area-to-displacement ratio of 17.8 with the ISO reference sail and 20.5 with a 135 percent genoa. The boat carries more rig than 58 percent of similar sailboats, which has been interpreted as slightly overrigged.
Theoretical hull speed is 6.8 knots. A calculated maximum near 5.2 knots was logged for the Volvo Penta MD2020 version.
Engine and Systems
Several engine options were offered, including an inboard Volvo Penta diesel and an MD2020 paired with a saildrive. The specification record also lists the 18-horsepower Volvo Penta MD2002 as a known installation.
Unlike a conventional shaft log, the saildrive arrangement penetrates the hull structure.
Verdict
The Inferno 31 is a compact, slightly overrigged Swedish fractional sloop that combines moderate-racer performance with cruiser-grade stability. It’s best suited to a sailor who wants a small boat that sails like a bigger one.
Pros
- Lead fin keel and a 44 percent ballast ratio
- Solid-fiberglass hull and deck
- Slightly overrigged fractional sloop, with an SA/D of up to 20.5 using a 135 percent genoa
- Capsize screening value of 1.86 and Motion Comfort Ratio of 25.4
Cons
- The saildrive option complicates below-waterline servicing
- The lean 3.15 length-to-beam ratio limits interior volume compared with wider contemporaries
