J/70 vs Rob Roy 23
How do the J/70 and Rob Roy 23 compare? Below, their dimensions, displacement, sail area and the standard design ratios side by side, followed by a data-driven summary.
J/70 
Rob Roy 23 | J/70 | Rob Roy 23 | |
|---|---|---|
| Length overall | 22.7 ft6.93 m | 22.7 ft6.91 m |
| Waterline length | 20.5 ft6.24 m | 21.0 ft6.40 m |
| Beam | 7.4 ft2.25 m | 6.9 ft2.11 m |
| Draft | 4.9 ft1.50 m | 4.7 ft1.42 m |
| Displacement | 1,790 lb812 kg | 2,800 lb1,270 kg |
| Ballast | 628 lb285 kg | 900 lb408 kg |
| Sail area | 226 ft²21.0 m² | 255 ft²23.7 m² |
| SA / Displacement | 24.53 | 20.54 |
| Displacement / Length | 93 | 135 |
| Comfort ratio | 9.1 | 15.3 |
| Capsize screening | 2.43 | 1.96 |
| Hull speed (kn) | 6.1 | 6.1 |
J/70 vs Rob Roy 23: the short version
- The J/70 and Rob Roy 23 are close in length (22.7 ft6.93 m vs 22.7 ft6.91 m ).
- The Rob Roy 23 is heavier, displacing about 56% more, which usually means a steadier but slower-to-accelerate hull.
- On sail area/displacement the J/70 carries the more powerful rig (24.5 vs 20.5), favouring lighter-air performance.
- The Rob Roy 23 scores higher on the Brewer comfort ratio, suggesting an easier motion in a seaway.
- By the capsize screening formula the Rob Roy 23 rates better for offshore work (1.96 vs 2.43).
Ratios are guidelines computed from published specs; condition, layout and gear matter as much as the numbers.