J/70
J BOATS · Rod Johnstone · 2012
Updated
The J/70 is a 6.94 m planing racing yacht designed by Rod Johnstone and built by J BOATS, first launched in 2012. It races in Sportboat. Across the measured fleet it goes better than its own numbers promise, ahead of 56% of the designs it races against. It comes alive as the breeze builds, and gives time away in the light.
Goes better than its own measurements promise, and does it better than 56% of the boats it races against.
13th of 28 in its class.
Not verified. On planing hulls this score has no match in the race results we hold: designs scoring the same win anywhere from one race in ten to seven in ten. Read it as what the measurements say, not as a ranking.
This design has been found in real race results — 138 starts across 11 events — not only in measurement files.
Length
6.94 m
22′ 9″
Beam
2.26 m
Draft
1.45 m
Displacement
0.8 t
Sail area
26 m²
On the podium
Where a J/70 finishes when she goes racing.
On the podium
46%
of 138 starts by 11 boats
Wins
20%
Read from 138 starts by 11 boats between 2021 and 2026, counting races with six boats or more.
Recent regattas
The latest events where a J/70 was on the start line, named as the organisers publish them.
54° Campionato Invernale Vela d'Altura del Golfo di Napoli2026
Tirsdagsregatta ÅSS2026- Stavanger Singlehanded2026
Republic Cup 2025 Offshore Race2025- Vesuvio Race2025
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
49%
of these races end on the podium
Offshore & coastal
—
Not enough data yet: 6 races over 10 NM carry a published distance.
Who she races against
The designs a J/70 actually lines up with, most often first. The bar shows how those meetings ended.
Also met, too few times for a figure:
Surprise (6 meetings), First 44.7 (3 meetings), Maxi 105 (1 meeting), Swan 42 (1 meeting), Bh 36 (1 meeting), JPK 10.30 (2 meetings), X-332 (1 meeting), Sun Fast 3200 (1 meeting), Grand Soleil 46 (Carkeek) (2 meetings), First 45 (Briand) (2 meetings), First 31.7 (4 meetings), Comet 105 (2 meetings), Sun Odyssey 40 (2 meetings)
Some of the boats it races against
How the J/70 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
4.57
39°
Beam reach
8.54
90°
Broad reach
12.36
135°
Downwind VMG
9.34
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.
This is a boat that wants breeze. Give it a fresh day and long legs and it delivers more than it promised; in a drifter it is working uphill.
Where it gains
Its best ground is off the wind in a strong breeze, where it does more than its size and sail area promise, and by a margin worth having. It holds that advantage running deep as well, so the gain is not down to one leg of the course.
Where it pays
It falls short to windward in a strong breeze, giving away time it never gets back. That is a hull that wants to get up and go, and needs pressure to do it.
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 4.0 kn either way.
At 10 knots this design makes back more than its rating asks on the broad reach.
How fast is a J/70
Boat speed in knots, by true wind angle and wind strength.
| Angle | 6 kn | 10 kn | 14 kn | 20 kn |
|---|---|---|---|---|
| Beat VMG | 3.03 | 4.20 | 4.58 | 4.57 |
| 52° | 4.64 | 6.03 | 6.46 | 6.60 |
| 60° | 4.90 | 6.20 | 6.75 | 6.96 |
| 75° | 5.07 | 6.35 | 7.16 | 7.68 |
| 90° | 5.42 | 6.68 | 7.29 | 8.54 |
| 110° | 5.53 | 7.13 | 8.22 | 9.59 |
| 120° | 5.39 | 7.03 | 8.71 | 10.60 |
| 135° | 4.86 | 6.58 | 8.18 | 12.36 |
| 150° | 4.11 | 5.98 | 7.15 | 10.78 |
| Run VMG | 3.56 | 5.19 | 6.19 | 9.34 |
How they are set up
The range each sail spans across the fleet.
Most run a fixed propeller. A bowsprit is standard across the fleet. Crew weight is declared around 340 kg.
Rigging
J/70 rig and sail dimensions
A J/70 carries 7.97 m of mainsail hoist on a 2.88 m boom, a forestay 8.15 m above the deck and a 4.03 m bowsprit. Typical figures across the 54 boats measured under the current VPP, with the range each one spans.
Rig
Sails
The spinnaker spreads widest of all — 45 to 50 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.