Companion 21 vs San Juan 21
How do the Companion 21 and San Juan 21 compare? Below, their dimensions, displacement, sail area and the standard design ratios side by side, followed by a data-driven summary.
Companion 21 
San Juan 21 | Companion 21 | San Juan 21 | |
|---|---|---|
| Length overall | 20.5 ft6.25 m | 20.5 ft6.25 m |
| Waterline length | 16.5 ft5.03 m | 17.5 ft5.33 m |
| Beam | 7.1 ft2.16 m | 7.0 ft2.13 m |
| Draft | 2.8 ft0.84 m | 4.0 ft1.22 m |
| Displacement | 3,100 lb1,406 kg | 1,250 lb567 kg |
| Ballast | 1,000 lb454 kg | 400 lb181 kg |
| Sail area | 218 ft²20.3 m² | 193 ft²17.9 m² |
| SA / Displacement | 16.41 | 26.61 |
| Displacement / Length | 308 | 104 |
| Comfort ratio | 19.9 | 7.9 |
| Capsize screening | 1.94 | 2.60 |
| Hull speed (kn) | 5.4 | 5.6 |
Companion 21 vs San Juan 21: the short version
- The Companion 21 and San Juan 21 are close in length (20.5 ft6.25 m vs 20.5 ft6.25 m ).
- The Companion 21 is heavier, displacing about 148% more, which usually means a steadier but slower-to-accelerate hull.
- On sail area/displacement the San Juan 21 carries the more powerful rig (26.6 vs 16.4), favouring lighter-air performance.
- The Companion 21 scores higher on the Brewer comfort ratio, suggesting an easier motion in a seaway.
- By the capsize screening formula the Companion 21 rates better for offshore work (1.94 vs 2.60).
Ratios are guidelines computed from published specs; condition, layout and gear matter as much as the numbers.