Open 5.70 Buyer's Guide
The Open 5.70 is a 5.70-meter one-design sportboat built by Phileas Boats and designed by Groupe Finot, a trailerable monohull that blends dinghy speed with a lifting keel and twin rudders. On the used market it draws buyers who want catamaran-style performance in a monohull they can ramp-launch and store on land, and its origins as a schools-and-clubs design mean the open cockpit and simple rig suit new sailors. Shopping one means weighing the open cockpit against the rig’s catamaran hardware and the shallow-water keel mode.
Layouts on the Used Market
Every Open 5.70 shares the same essential plan: a large open cockpit with no cabin, built around a 2.55-meter beam that maximizes road transport width. The wide cockpit lets crews shift weight fore and aft, and the twin retractable rudders paired with a lifting T-keel define the helm. Keel travel is the main layout variable—fully down it draws 5 feet 9 inches, while the shallow-water block sets it at 4 foot 6 inches for trailering or thin water. There is no enclosed berth or head; the boat is pure cockpit and deck.
Equipment and Common Upgrades
The commonly fitted racing asset is the asymmetric spinnaker, a 32-square-meter kite on a telescopic boomsprit that one sailor can hoist and douse alone. Beyond that, the rig itself carries over catamaran gear: the rotating wingmast and boom are shared with the Hobie Tiger, and the stern traveler uses the extreme beam for a long adjustment span. Buyers should confirm the mast rotation bearings, the bolt-jack rig tensioner under the mast, and the diamond spreaders that turn with the mast, since these are the moving parts that make the boat go uphill.
What to Inspect
The foam-cored molded structure of the hull is fiberglass-reinforced polyester with a 15mm PVC foam-core sandwich deck and a large fixed longitudinal member bonding deck to hull built out of glass fiber reinforced polyester. The builder claimed the boat is unsinkable through this construction according to U.S. importer Jerome Sammarcelli, so check the sealed volumes and core for undocumented repairs. The keel has two draft settings via its block at 1.40 meters; verify the lifting mechanism and the lead bulb-to-fin joint, since the 150 kg bulb and 30 kg fin are the ballast. Twin rudders should retract smoothly, and the wingmast’s shrouds, forestay, and traveler should show no elongated holes from the 573-pound class max crew loading.
Availability and Buyer’s Takeaway
The Open 5.70 typically appears in Spain and the United Kingdom. For a buyer, the short list is: confirm the foam core and sealed buoyancy are intact, exercise the keel lift and rudder retraction, and check the catamaran-derived mast rotation gear. A sound example offers a trailerable, unsinkable sportboat that races three in Europe or two in testing, with a 30-minute setup and mid-teen speed potential.
Price & volume trends
Monthly asking-price and listing-volume trends for the Open 5.70. The line shows the median ask each month; the bars show how many listings appeared.
Monthly breakdown · 3 rows
| Month | Listings | Median ask | Δ vs. last mo. |
|---|---|---|---|
| Sep 25 | 1 | $8,156 | — |
| Jun 26 | 1 | $13,594 | +66.7% |
| Jul 26 | 1 | $11,068 | -18.6% |
Where they're listed
Open 5.70 listings appear across 2 countries. Spain has the most listings with 2 (66.7%), followed by United Kingdom.
Country view
3 listings · 2 countries| Country | Median ask | Listings · 12 mo | Active · 90 d | Share |
|---|---|---|---|---|
| Spain | $9,612 | 2 | 1 | 66.7% |
| United Kingdom | $13,594 | 1 | 1 | 33.3% |
Comparable models
Similar length, displacement, and era. Open a row to compare that model's market page.
Similar boats to compare
2 similar designs| Model | LOA | Median ask | Listings · 12 mo | Active · 90 d |
|---|---|---|---|---|
| J-Boats J/70 | 22.74' | $ 44,000 | 37 | 8 |
| Phileas Boats 5.70You are here | — | $ 11,068 | 3 | 2 |