Swan 391 vs Swan 55 Frers
How do the Swan 391 and Swan 55 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 55 Frers | Swan 391 | Swan 55 Frers | |
|---|---|---|
| Length overall | 33.1 ft10.08 m | 42.9 ft13.07 m |
| Waterline length | 33.1 ft10.08 m | 42.9 ft13.07 m |
| Beam | 12.4 ft3.79 m | 15.9 ft4.85 m |
| Draft | 7.2 ft2.19 m | 8.5 ft2.60 m |
| Displacement | 18,900 lb8,573 kg | 52,029 lb23,600 kg |
| Ballast | 6,800 lb3,084 kg | 19,900 lb9,026 kg |
| Sail area | 767 ft²71.3 m² | 1,147 ft²106.6 m² |
| SA / Displacement | 17.30 | 13.17 |
| Displacement / Length | 233 | 295 |
| Comfort ratio | 30.8 | 47.1 |
| Capsize screening | 1.87 | 1.70 |
| Hull speed (kn) | 7.7 | 8.8 |
Swan 391 vs Swan 55 Frers: the short version
- The Swan 55 Frers is the larger boat at 42.9 ft13.07 m LOA versus 33.1 ft10.08 m for the Swan 391.
- The Swan 55 Frers is heavier, displacing about 175% more, which usually means a steadier but slower-to-accelerate hull.
- On sail area/displacement the Swan 391 carries the more powerful rig (17.3 vs 13.2), favouring lighter-air performance.
- The Swan 55 Frers scores higher on the Brewer comfort ratio, suggesting an easier motion in a seaway.
- By the capsize screening formula the Swan 55 Frers rates better for offshore work (1.70 vs 1.87).
Ratios are guidelines computed from published specs; condition, layout and gear matter as much as the numbers.