J/109
Dimensions
| Hull type | Monohull |
| LOA | 35.25 ft (10.74 m) |
| LWL | 30.50 ft (9.30 m) |
| Beam | 11.50 ft (3.51 m) |
| Draft | 7.00 ft (2.13 m) |
| Displacement | 10,900 lbs (4,944 kg) |
| Ballast | 3,900 lbs (1,769 kg) |
| Sail area (main) | 335 sq ft (31.1 m²) |
| Sail area (jib) | 309 sq ft (28.7 m²) |
| Sail area (total) | 644 sq ft (59.8 m²) |
| Rig type | sloop |
| Keel type | fin_with_bulb |
| Rudder type | Spade |
| Rudder material | GRP / E-glass fiberglass |
| Rudder shaft | Aluminum |
| Fuel capacity | 18.5 gal |
| Water capacity | 25.4 gal |
| Designer | Alan Johnstone |
Construction
Sources
Dimensions/displacement/sail area per jboats.com tech specs (matches sailboatdata.com convention: 100% SA = fore-triangle + main). Main/jib split computed from published I/J/P/E rig dimensions (I=46.50, J=13.30, P=43.25, E=15.50). Hull layup verified from J/Boats' own construction description: Baltek balsa/biaxial-unidirectional glass, single vinylester resin, SCRIMP infusion. Mast explicitly described as tapered aluminum. Verified 2026-07-09. [Rudder/tankage/electrical update, 2026-07-16]: Rudder: balanced high-aspect spade, biaxial/unidirectional glass over an anodized aluminum stock, self-aligning bearings. Fuel 85L/18.5gal under the aft cabin berth; water 96L/~25.4gal under the starboard saloon berth. No holding-tank or electrical-system data found.