Swan 391 vs Swan 42
How do the Swan 391 and Swan 42 compare? Below, their dimensions, displacement, sail area and the standard design ratios side by side, followed by a data-driven summary.
Swan 391 
Swan 42 | Swan 391 | Swan 42 | |
|---|---|---|
| Length overall | 33.1 ft10.08 m | 34.0 ft10.35 m |
| Waterline length | 33.1 ft10.08 m | 34.0 ft10.35 m |
| Beam | 12.4 ft3.79 m | 13.0 ft3.95 m |
| Draft | 7.2 ft2.19 m | 7.9 ft2.40 m |
| Displacement | 18,900 lb8,573 kg | 23,810 lb10,800 kg |
| Ballast | 6,800 lb3,084 kg | 9,200 lb4,173 kg |
| Sail area | 767 ft²71.3 m² | 1,029 ft²95.6 m² |
| SA / Displacement | 17.30 | 19.89 |
| Displacement / Length | 233 | 271 |
| Comfort ratio | 30.8 | 35.7 |
| Capsize screening | 1.87 | 1.80 |
| Hull speed (kn) | 7.7 | 7.8 |
Swan 391 vs Swan 42: the short version
- The Swan 42 is the larger boat at 34.0 ft10.35 m LOA versus 33.1 ft10.08 m for the Swan 391.
- The Swan 42 is heavier, displacing about 26% more, which usually means a steadier but slower-to-accelerate hull.
- On sail area/displacement the Swan 42 carries the more powerful rig (19.9 vs 17.3), favouring lighter-air performance.
- The Swan 42 scores higher on the Brewer comfort ratio, suggesting an easier motion in a seaway.
- By the capsize screening formula the Swan 42 rates better for offshore work (1.80 vs 1.87).
Ratios are guidelines computed from published specs; condition, layout and gear matter as much as the numbers.