Seidelmann 37 vs Sonar
How do the Seidelmann 37 and Sonar compare? Below, their dimensions, displacement, sail area and the standard design ratios side by side, followed by a data-driven summary.
Seidelmann 37 
Sonar | Seidelmann 37 | Sonar | |
|---|---|---|
| Length overall | 36.8 ft11.23 m | 23.0 ft7.00 m |
| Waterline length | 31.0 ft9.45 m | 19.9 ft6.07 m |
| Beam | 12.0 ft3.66 m | 7.9 ft2.40 m |
| Draft | 5.9 ft1.80 m | 3.9 ft1.19 m |
| Displacement | 12,000 lb5,443 kg | 2,100 lb953 kg |
| Ballast | 5,900 lb2,676 kg | 930 lb422 kg |
| Sail area | 643 ft²59.7 m² | 265 ft²24.6 m² |
| SA / Displacement | 19.63 | 25.86 |
| Displacement / Length | 180 | 119 |
| Comfort ratio | 20.7 | 10.0 |
| Capsize screening | 2.10 | 2.46 |
| Hull speed (kn) | 7.5 | 6.0 |
Seidelmann 37 vs Sonar: the short version
- The Seidelmann 37 is the larger boat at 36.8 ft11.23 m LOA versus 23.0 ft7.00 m for the Sonar.
- The Seidelmann 37 is heavier, displacing about 471% 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 19.6), favouring lighter-air performance.
- The Seidelmann 37 scores higher on the Brewer comfort ratio, suggesting an easier motion in a seaway.
- By the capsize screening formula the Seidelmann 37 rates better for offshore work (2.10 vs 2.46).
Ratios are guidelines computed from published specs; condition, layout and gear matter as much as the numbers.