Kirby 23 vs Sonar
How do the Kirby 23 and Sonar compare? Below, their dimensions, displacement, sail area and the standard design ratios side by side, followed by a data-driven summary.
Kirby 23 
Sonar | Kirby 23 | Sonar | |
|---|---|---|
| Length overall | 23.0 ft7.01 m | 23.0 ft7.00 m |
| Waterline length | 18.8 ft5.73 m | 19.9 ft6.07 m |
| Beam | 7.8 ft2.36 m | 7.9 ft2.40 m |
| Draft | 3.9 ft1.19 m | 3.9 ft1.19 m |
| Displacement | 2,400 lb1,089 kg | 2,100 lb953 kg |
| Ballast | 900 lb408 kg | 930 lb422 kg |
| Sail area | 273 ft²25.4 m² | 265 ft²24.6 m² |
| SA / Displacement | 24.37 | 25.86 |
| Displacement / Length | 161 | 119 |
| Comfort ratio | 12.1 | 10.0 |
| Capsize screening | 2.32 | 2.46 |
| Hull speed (kn) | 5.8 | 6.0 |
Kirby 23 vs Sonar: the short version
- The Kirby 23 and Sonar are close in length (23.0 ft7.01 m vs 23.0 ft7.00 m ).
- The Kirby 23 is heavier, displacing about 14% more, which usually means a steadier but slower-to-accelerate hull.
- On sail area/displacement the Sonar carries the more powerful rig (25.9 vs 24.4), favouring lighter-air performance.
- The Kirby 23 scores higher on the Brewer comfort ratio, suggesting an easier motion in a seaway.
- By the capsize screening formula the Kirby 23 rates better for offshore work (2.32 vs 2.46).
Ratios are guidelines computed from published specs; condition, layout and gear matter as much as the numbers.