Swan 431
Description
The Swan 431 is a classic 43'2" (13.2 m) fiberglass monohull sailboat designed by Sparkman & Stephens (design #2238-C1) as a seaworthy cruiser-racer optimized for offshore performance under the IOR rule, blending speed, stability, and family cruising comfort in a heavy-displacement package. Built by Nautor Swan in Pietarsaari, Finland, from 1976 to 1978 with 32 hulls produced, it features a fin keel with skeg-hung rudder for protected steering and balanced handling, a masthead sloop rig with aluminum spars, and elegant lines with a raked stem, moderate beam, and counter stern—delivering a hull speed of 7.8 knots and a high displacement/length ratio (around 310) that classifies it as a medium-heavy cruiser, stiff and forgiving in heavy weather with a ballast/displacement ratio of 40% for excellent righting capability, though its sail area/displacement ratio (15.9) makes it underpowered in light airs. Constructed with solid hand-laid fiberglass hulls and balsa-cored decks for durability, the teak-rich interior sleeps 6–8 in a practical layout with V-berth forward, saloon settees, U-shaped galley, nav station, and quarter berth, offering generous volume and ventilation for bluewater passages.
Construction Details
| Designer | Sparkman and Stephens |
|---|---|
| Builder | Nautor |
| Length | 43.000 ft |
| LOA | 43.250 ft |
| LWL | 33.330 ft |
| Beam | 13.410 ft |
| Displacement | 26500 lb |
| Max Draft | 7.400 ft |
The standard boat dimensions
| i | 59 ft |
|---|---|
| j | 17.95 ft |
| p | 53.25 ft |
| e | 13.75 ft |
| p2 | - |
| e2 | - |
| i2 | - |
| j2 | - |
| I | J | P | E | P2 | E2 | I2 | J2 |
|---|---|---|---|---|---|---|---|
| 59 ft | 17.95 ft | 53.25 ft | 13.75 ft | - | - | - | - |
Blueprints
Sails
| Sail Type | MAINSAIL |
|---|---|
| Luff | * 53.25 ft - (16231 mm) |
| Foot | * 13.75 ft - (4191 mm) |
| Leech | * 54.41 ft - (16584 mm) |
| Tack Angle | * 88 ° |
| Diagonal | * 54.53 ft - (16621 mm) |
| Head (inches) | * 6 in - (152 mm) |
| Area | 365.74 ft² |
| Sail Type | JIBSAIL |
|---|---|
| Luff | * 49.34 ft - (15039 mm) |
| Foot | * 23.58 ft - (7187 mm) |
| Leech | * 43.19 ft - (13164 mm) |
| Percentage LP | * 115 % |
| Length Perpendicular | * 20.64 ft - (6291 mm) |
| Deck Angle | * 12 ° |
| Area | 509.2 ft² |
| Sail Type | GENOA |
|---|---|
| Luff | * 58.59 ft - (17858 mm) |
| Foot | * 28.83 ft - (8787 mm) |
| Leech | * 55.29 ft - (16852 mm) |
| Percentage LP | * 150 % |
| Length Perpendicular | * 26.93 ft - (8208 mm) |
| Deck Angle | * 4 ° |
| Area | 788.83 ft² |
| Sail Type | SPINNAKER |
|---|---|
| Stays | * 58.59 ft - (17858 mm) |
| MidGirth | * 32.31 ft - (9848 mm) |
| Foot | * 32.31 ft - (9848 mm) |
| Perc LP | * 180 % |
| Area | 1609.09 ft² |
Disclaimer. Boats are not all the same -- even when produced in the same factory of the same model. Sailrite does its best to publish accurate dimensions, but we often find it worthwhile to have our customers measure their boats carefully before we produce kits for them. You should take the same precautions, especially when the data is not from Sailrite. The information on this site is not guaranteed to be accurate. Sailrite offers this content as a service to our community, but takes no responsibility for the reliability of the data provided.