Swan 391 vs Swan 77
How do the Swan 391 and Swan 77 compare? Below, their dimensions, displacement, sail area and the standard design ratios side by side, followed by a data-driven summary.
Swan 391 
Swan 77 | Swan 391 | Swan 77 | |
|---|---|---|
| Length overall | 33.1 ft10.08 m | 60.3 ft18.38 m |
| Waterline length | 33.1 ft10.08 m | 60.3 ft18.38 m |
| Beam | 12.4 ft3.79 m | 19.7 ft6.00 m |
| Draft | 7.2 ft2.19 m | 11.2 ft3.40 m |
| Displacement | 18,900 lb8,573 kg | 112,436 lb51,000 kg |
| Ballast | 6,800 lb3,084 kg | 39,683 lb18,000 kg |
| Sail area | 767 ft²71.3 m² | 2,811 ft²261.2 m² |
| SA / Displacement | 17.30 | 19.31 |
| Displacement / Length | 233 | 229 |
| Comfort ratio | 30.8 | 54.5 |
| Capsize screening | 1.87 | 1.63 |
| Hull speed (kn) | 7.7 | 10.4 |
Swan 391 vs Swan 77: the short version
- The Swan 77 is the larger boat at 60.3 ft18.38 m LOA versus 33.1 ft10.08 m for the Swan 391.
- The Swan 77 is heavier, displacing about 495% more, which usually means a steadier but slower-to-accelerate hull.
- On sail area/displacement the Swan 77 carries the more powerful rig (19.3 vs 17.3), favouring lighter-air performance.
- The Swan 77 scores higher on the Brewer comfort ratio, suggesting an easier motion in a seaway.
- By the capsize screening formula the Swan 77 rates better for offshore work (1.63 vs 1.87).
Ratios are guidelines computed from published specs; condition, layout and gear matter as much as the numbers.