Swan 391 vs Swan 57 Mk II
How do the Swan 391 and Swan 57 Mk II compare? Below, their dimensions, displacement, sail area and the standard design ratios side by side, followed by a data-driven summary.
Swan 391 
Swan 57 Mk II | Swan 391 | Swan 57 Mk II | |
|---|---|---|
| Length overall | 33.1 ft10.08 m | 44.5 ft13.57 m |
| Waterline length | 33.1 ft10.08 m | 44.5 ft13.57 m |
| Beam | 12.4 ft3.79 m | 15.9 ft4.85 m |
| Draft | 7.2 ft2.19 m | 7.2 ft2.20 m |
| Displacement | 18,900 lb8,573 kg | 54,013 lb24,500 kg |
| Ballast | 6,800 lb3,084 kg | 20,348 lb9,230 kg |
| Sail area | 767 ft²71.3 m² | 1,350 ft²125.4 m² |
| SA / Displacement | 17.30 | 15.12 |
| Displacement / Length | 233 | 273 |
| Comfort ratio | 30.8 | 47.1 |
| Capsize screening | 1.87 | 1.68 |
| Hull speed (kn) | 7.7 | 8.9 |
Swan 391 vs Swan 57 Mk II: the short version
- The Swan 57 Mk II is the larger boat at 44.5 ft13.57 m LOA versus 33.1 ft10.08 m for the Swan 391.
- The Swan 57 Mk II is heavier, displacing about 186% 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 15.1), favouring lighter-air performance.
- The Swan 57 Mk II scores higher on the Brewer comfort ratio, suggesting an easier motion in a seaway.
- By the capsize screening formula the Swan 57 Mk II rates better for offshore work (1.68 vs 1.87).
Ratios are guidelines computed from published specs; condition, layout and gear matter as much as the numbers.