Inferno 31
Finngulf · Håkan Södergren · 1985
Updated
The Inferno 31 is a 9.45 m heavy displacement racing yacht designed by Håkan Södergren and built by Finngulf, first launched in 1985. It races in Class C.
Length
9.45 m
31′ 0″
Beam
3.02 m
Draft
1.64 m
Displacement
4.4 t
Sail area
62 m²
On the podium
Where a Inferno 31 finishes when she goes racing.
On the podium
50%
of 12 starts by 2 boats
Wins
8%
Read from 12 starts by 2 boats between 2025 and 2026, counting races with six boats or more.
Recent regattas
The latest events where a Inferno 31 was on the start line, named as the organisers publish them.
Someron Säästöpankin Kotka Cup2026- Helsinki-Kotka Race2026
- Extra Marine Yöpurjehdus2026
- Garmin ORC DH European Championship2025
Raced one we are missing?
Report a regattaRound the buoys, or offshore
A short windward-leeward and a night at sea ask different things of a boat. Here is how this one does in each.
Round the buoys
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Not enough data yet: no races of 10 NM or less carry a published distance.
Offshore & coastal
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Not enough data yet: 2 races over 10 NM carry a published distance.
Who she races against
The designs a Inferno 31 actually lines up with, most often first. The bar shows how those meetings ended.
Also met, too few times for a figure:
Express (7 meetings), X-332 (7 meetings), First 36.7 (6 meetings), X-34 (2 meetings), First 35 (Farr) (4 meetings), First 34.7 (2 meetings), First 31.7 (6 meetings), First 30 (Kouyoumdjian) (2 meetings), Bavaria 35 (2 meetings), Fareast 28 (2 meetings), Ridas 35 (2 meetings), X-362 (2 meetings), Archambault 31 (2 meetings), Linjett 33 (2 meetings), Seascape 27 (2 meetings), X-99 (1 meeting), Finngulf 37 (1 meeting), Dehler 30 OD (1 meeting), Sera 33 (1 meeting)
Some of the boats it races against
How the Inferno 31 has fared against each of them, boat against boat on corrected time. Ordered by how often the two meet, not by who wins.
Speed at every angle
The shape of this design's speed, drawn from the measured fleet. Pick a wind and watch it stretch.
Upwind VMG
4.62
39°
Beam reach
7.36
90°
Broad reach
8.07
135°
Downwind VMG
7.19
170°
Speed in knots at 20 knots of true wind. Green marks the angles that pay: the closest useful beat and the deepest run worth sailing.
Where it wins and where it pays
Every boat is judged against its own measurements — length, weight, sail area. The quicker those say it should be, the more it has to deliver just to break even. Going fast is not enough: it has to go faster than its own numbers promised.
Soft conditions suit it. In the light it does more than its numbers promise, and gives some of that back when the wind arrives.
Where it gains
Its best ground is on the beat when the breeze is soft, where it outruns what it looks like on paper, and by a margin worth having. It holds that advantage across the wind as well, so the gain is not down to one leg of the course.
Where it pays
It falls short cracked off once it pipes up, giving away time it never gets back. That is weight that has to be driven rather than released.
Above the line it delivers more than promised and gains on the fleet. Below, it falls short. Move the wind: plenty of boats sit on one side in the light and the other when it blows.
Full width is 0.4 kn either way.
At 10 knots this design makes back more than its rating asks on the upwind.
How fast is a Inferno 31
Boat speed in knots, by true wind angle and wind strength.
| Angle | 6 kn | 10 kn | 14 kn | 20 kn |
|---|---|---|---|---|
| Beat VMG | 3.33 | 4.29 | 4.56 | 4.62 |
| 52° | 5.05 | 6.20 | 6.46 | 6.56 |
| 60° | 5.29 | 6.36 | 6.63 | 6.75 |
| 75° | 5.49 | 6.50 | 6.84 | 7.05 |
| 90° | 5.41 | 6.57 | 6.96 | 7.36 |
| 110° | 5.29 | 6.64 | 7.19 | 7.83 |
| 120° | 5.11 | 6.58 | 7.21 | 8.07 |
| 135° | 4.61 | 6.33 | 7.04 | 8.07 |
| 150° | 3.91 | 5.81 | 6.75 | 7.71 |
| Run VMG | 3.38 | 5.06 | 6.25 | 7.19 |
How they are set up
The range each sail spans across the fleet.
Nearly all carry a folding propeller. Crew weight is declared around 460 kg.
Rigging
Inferno 31 rig and sail dimensions
A Inferno 31 carries 12.27 m of mainsail hoist on a 4.23 m boom, a forestay 11.69 m above the deck and a 4.20 m bowsprit. Typical figures across the 6 boats measured under the current VPP, with the range each one spans.
Rig
Sails
The spinnaker spreads widest of all — 57 to 67 m² depending on bowsprit and set-up. Before ordering a sail, read the figure on your own measurement record rather than the typical one for the design.