Sly 42
Sly Yachts · Marco Lostuzzi · 2007
Updated
The Sly 42 is a 12.84 m semi-displacement racing yacht designed by Marco Lostuzzi and built by Sly Yachts, first launched in 2007. It races in Class A. Across the measured fleet it goes better than its own numbers promise, ahead of 62% of the designs it races against.
Goes better than its own measurements promise, and does it better than 62% of the boats it races against.
18th of 46 in its class.
Updated — First Race Edge for this design. Enough boats of this design have now been measured to rank it. It is strongest in light and heavy air.
This design has been found in real race results — 45 starts across 24 events — not only in measurement files.
Length
12.84 m
42′ 2″
Beam
3.80 m
Draft
2.57 m
Displacement
7.1 t
Sail area
104 m²
On the podium
Where a Sly 42 finishes when she goes racing.
On the podium
9%
of 45 starts by 5 boats
Wins
2%
Read from 45 starts by 5 boats between 2011 and 2026, counting races with six boats or more.
Recent regattas
The latest events where a Sly 42 was on the start line, named as the organisers publish them.
Aegean 6002026
73° Loro Piana Giraglia2026- 42ος Ιστιοπλοικος Αγωνας Α/θ ¨Πορος ΄26¨2026
- Regata dei Cinque Fari2025
- Edison Next Italian Offshore Sailing Championship - Campionato Italiano Assoluto d’Altura2025
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
18%
of these races end on the podium
Offshore & coastal
0%
of these races end on the podium
Sharper round the buoys. Short courses reward acceleration and manoeuvring, and that is where this design makes its money.
Who she races against
The designs a Sly 42 actually lines up with, most often first. The bar shows how those meetings ended.
Some of the boats it races against
How the Sly 42 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
6.04
37°
Beam reach
9.82
90°
Broad reach
12.20
135°
Downwind VMG
9.30
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.
It needs pressure to show what it can do. On a windy coastal course it is in its element; on a light-air windward-leeward it has to be sailed well to hold on.
Where it gains
Its best ground is on a broad reach in a strong breeze, where it outruns what it looks like on paper, and by a margin worth having. It holds that advantage downwind as well, so the gain is not down to one leg of the course.
Where it pays
There is no condition where it falls away badly, which is worth something over a season of mixed weather.
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 1.0 kn either way.
At 10 knots this design makes back more than its rating asks on the broad reach.
How fast is a Sly 42
Boat speed in knots, by true wind angle and wind strength.
| Angle | 6 kn | 10 kn | 14 kn | 20 kn |
|---|---|---|---|---|
| Beat VMG | 4.01 | 5.42 | 5.82 | 6.04 |
| 52° | 6.10 | 7.83 | 8.17 | 8.38 |
| 60° | 6.42 | 8.05 | 8.43 | 8.67 |
| 75° | 6.64 | 8.22 | 8.80 | 9.24 |
| 90° | 6.54 | 8.27 | 9.03 | 9.82 |
| 110° | 6.70 | 8.61 | 9.45 | 10.45 |
| 120° | 6.55 | 8.58 | 9.77 | 11.08 |
| 135° | 5.86 | 8.18 | 9.46 | 12.20 |
| 150° | 4.90 | 7.30 | 8.68 | 10.74 |
| Run VMG | 4.24 | 6.32 | 7.56 | 9.30 |
How they are set up
The range each sail spans across the fleet.
Nearly all carry a folding propeller. A bowsprit is standard across the fleet. Crew weight is declared around 800 kg.
Rigging
Sly 42 rig and sail dimensions
A Sly 42 carries 17.15 m of mainsail hoist on a 5.66 m boom, a forestay 16.94 m above the deck and a 6.23 m bowsprit. Typical figures across the 8 boats measured under the current VPP, with the range each one spans.
Rig
Sails
The spinnaker spreads widest of all — 146 to 188 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.