Swan 391 vs Swan 53 Mk I
How do the Swan 391 and Swan 53 Mk I compare? Below, their dimensions, displacement, sail area and the standard design ratios side by side, followed by a data-driven summary.
Swan 391 
Swan 53 Mk I | Swan 391 | Swan 53 Mk I | |
|---|---|---|
| Length overall | 33.1 ft10.08 m | 42.5 ft12.94 m |
| Waterline length | 33.1 ft10.08 m | 42.5 ft12.94 m |
| Beam | 12.4 ft3.79 m | 15.5 ft4.73 m |
| Draft | 7.2 ft2.19 m | 10.2 ft3.10 m |
| Displacement | 18,900 lb8,573 kg | 44,092 lb20,000 kg |
| Ballast | 6,800 lb3,084 kg | 18,518 lb8,400 kg |
| Sail area | 767 ft²71.3 m² | 1,342 ft²124.7 m² |
| SA / Displacement | 17.30 | 17.20 |
| Displacement / Length | 233 | 257 |
| Comfort ratio | 30.8 | 41.7 |
| Capsize screening | 1.87 | 1.76 |
| Hull speed (kn) | 7.7 | 8.7 |
Swan 391 vs Swan 53 Mk I: the short version
- The Swan 53 Mk I is the larger boat at 42.5 ft12.94 m LOA versus 33.1 ft10.08 m for the Swan 391.
- The Swan 53 Mk I is heavier, displacing about 133% 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 17.2), favouring lighter-air performance.
- The Swan 53 Mk I scores higher on the Brewer comfort ratio, suggesting an easier motion in a seaway.
- By the capsize screening formula the Swan 53 Mk I rates better for offshore work (1.76 vs 1.87).
Ratios are guidelines computed from published specs; condition, layout and gear matter as much as the numbers.