Swan 391 vs Swan 40 Frers
How do the Swan 391 and Swan 40 Frers compare? Below, their dimensions, displacement, sail area and the standard design ratios side by side, followed by a data-driven summary.
Swan 391 
Swan 40 Frers | Swan 391 | Swan 40 Frers | |
|---|---|---|
| Length overall | 33.1 ft10.08 m | 32.4 ft9.88 m |
| Waterline length | 33.1 ft10.08 m | 32.4 ft9.88 m |
| Beam | 12.4 ft3.79 m | 12.9 ft3.94 m |
| Draft | 7.2 ft2.19 m | 7.0 ft2.15 m |
| Displacement | 18,900 lb8,573 kg | 19,401 lb8,800 kg |
| Ballast | 6,800 lb3,084 kg | 6,990 lb3,171 kg |
| Sail area | 767 ft²71.3 m² | 830 ft²77.1 m² |
| SA / Displacement | 17.30 | 18.39 |
| Displacement / Length | 233 | 254 |
| Comfort ratio | 30.8 | 30.6 |
| Capsize screening | 1.87 | 1.92 |
| Hull speed (kn) | 7.7 | 7.6 |
Swan 391 vs Swan 40 Frers: the short version
- The Swan 391 is the larger boat at 33.1 ft10.08 m LOA versus 32.4 ft9.88 m for the Swan 40 Frers.
- On sail area/displacement the Swan 40 Frers carries the more powerful rig (18.4 vs 17.3), favouring lighter-air performance.
- The Swan 391 scores higher on the Brewer comfort ratio, suggesting an easier motion in a seaway.
- By the capsize screening formula the Swan 391 rates better for offshore work (1.87 vs 1.92).
Ratios are guidelines computed from published specs; condition, layout and gear matter as much as the numbers.