J/120
Dimensions
| Hull type | Monohull |
| LOA | 40.00 ft (12.19 m) |
| LWL | 35.00 ft (10.67 m) |
| Beam | 12.00 ft (3.66 m) |
| Draft | 7.00 ft (2.13 m) |
| Displacement | 13,900 lbs (6,305 kg) |
| Ballast | 6,000 lbs (2,722 kg) |
| Sail area (main) | 414 sq ft (38.5 m²) |
| Sail area (jib) | 366 sq ft (34.0 m²) |
| Sail area (total) | 780 sq ft (72.5 m²) |
| Rig type | sloop |
| Keel type | fin_with_bulb |
| Rudder type | Spade |
| Rudder material | GRP / E-glass fiberglass |
| Fuel capacity | 27 gal |
| Water capacity | 75 gal |
| Designer | Rod Johnstone |
Construction
Sources
Dimensions/displacement/sail area per jboats.com tech specs and sailboatdata.com; main/jib split computed from published I/J/P/E rig dimensions (I=50.50, J=14.50, P=46.50, E=17.80), sums to the published 780 sqft 100% SA. Hull layup (Baltek balsa composite, vinylester resin on outer layer, SCRIMP infusion) verified via J/Boats specification text. Mast material not explicitly stated on jboats.com tech-specs page for this model; defaulted to aluminum (standard for this era/model, no carbon option documented). Verified 2026-07-09. [Rudder/tankage/electrical update, 2026-07-16]: Rudder: balanced spade, unidirectional glass, large-diameter shaft (material not documented in available sources). Fuel 27gal (2 baffled tanks), water 75gal (2 baffled tanks under the settee). No holding-tank or electrical-system data found.