Impulse 21 vs Sirius 22
How do the Impulse 21 and Sirius 22 compare? Below, their dimensions, displacement, sail area and the standard design ratios side by side, followed by a data-driven summary.
Impulse 21 
Sirius 22 | Impulse 21 | Sirius 22 | |
|---|---|---|
| Length overall | 21.0 ft6.40 m | 21.0 ft6.40 m |
| Waterline length | 18.5 ft5.64 m | 18.8 ft5.71 m |
| Beam | 8.0 ft2.44 m | 7.9 ft2.41 m |
| Draft | 3.3 ft0.99 m | 5.0 ft1.52 m |
| Displacement | 1,300 lb590 kg | 2,000 lb907 kg |
| Ballast | 600 lb272 kg | 525 lb238 kg |
| Sail area | 207 ft²19.2 m² | 205 ft²19.0 m² |
| SA / Displacement | 27.81 | 20.66 |
| Displacement / Length | 92 | 135 |
| Comfort ratio | 6.5 | 10.1 |
| Capsize screening | 2.93 | 2.51 |
| Hull speed (kn) | 5.8 | 5.8 |
Impulse 21 vs Sirius 22: the short version
- The Impulse 21 and Sirius 22 are close in length (21.0 ft6.40 m vs 21.0 ft6.40 m ).
- The Sirius 22 is heavier, displacing about 54% more, which usually means a steadier but slower-to-accelerate hull.
- On sail area/displacement the Impulse 21 carries the more powerful rig (27.8 vs 20.7), favouring lighter-air performance.
- The Sirius 22 scores higher on the Brewer comfort ratio, suggesting an easier motion in a seaway.
- By the capsize screening formula the Sirius 22 rates better for offshore work (2.51 vs 2.93).
Ratios are guidelines computed from published specs; condition, layout and gear matter as much as the numbers.