J/70 vs J/80
How do the J/70 and J/80 compare? Below, their dimensions, displacement, sail area and the standard design ratios side by side, followed by a data-driven summary.
J/70 
J/80 | J/70 | J/80 | |
|---|---|---|
| Length overall | 22.7 ft6.93 m | 26.3 ft8.00 m |
| Waterline length | 20.5 ft6.24 m | 22.0 ft6.71 m |
| Beam | 7.4 ft2.25 m | 8.2 ft2.51 m |
| Draft | 4.9 ft1.50 m | 4.9 ft1.49 m |
| Displacement | 1,790 lb812 kg | 2,899 lb1,315 kg |
| Ballast | 628 lb285 kg | 1,400 lb635 kg |
| Sail area | 226 ft²21.0 m² | 337 ft²31.3 m² |
| SA / Displacement | 24.53 | 26.52 |
| Displacement / Length | 93 | 121 |
| Comfort ratio | 9.1 | 11.6 |
| Capsize screening | 2.43 | 2.31 |
| Hull speed (kn) | 6.1 | 6.3 |
J/70 vs J/80: the short version
- The J/80 is the larger boat at 26.3 ft8.00 m LOA versus 22.7 ft6.93 m for the J/70.
- The J/80 is heavier, displacing about 62% more, which usually means a steadier but slower-to-accelerate hull.
- On sail area/displacement the J/80 carries the more powerful rig (26.5 vs 24.5), favouring lighter-air performance.
- The J/80 scores higher on the Brewer comfort ratio, suggesting an easier motion in a seaway.
- By the capsize screening formula the J/80 rates better for offshore work (2.31 vs 2.43).
Ratios are guidelines computed from published specs; condition, layout and gear matter as much as the numbers.