BRUCE ROBERTS 31
Description
The Bruce Roberts 31, also known as the Classic 31, is a robust and traditional gaff-rigged cutter sailboat designed in the 1970s by naval architect Bruce Roberts for affordable home construction in fiberglass, steel, or wood-epoxy, offering cutter or ketch rigging options ideal for coastal cruising or extended voyages with a seaworthy long-keel hull emphasizing stability and simplicity. At 31 feet 11 inches LOA with a 24-foot 2-inch waterline, 10-foot beam, and 4-foot 6-inch draft, it boasts a displacement of around 14,200 pounds for solid performance, accommodating a sail plan with foretriangle height of 37.8 feet and mainsail luff of 33.5 feet, powered by a typical 20–30 hp auxiliary diesel, and featuring a cozy interior for 4–6 berths with 6 feet of headroom. Popular among DIY builders for its straightforward plans and proven durability—over hundreds built worldwide
The standard boat dimensions
| i | 40.75 ft |
|---|---|
| j | 13 ft |
| p | - |
| e | - |
| p2 | - |
| e2 | - |
| i2 | - |
| j2 | - |
| I | J | P | E | P2 | E2 | I2 | J2 |
|---|---|---|---|---|---|---|---|
| 40.75 ft | 13 ft | - | - | - | - | - | - |
Documents
Blueprints
Sails
BRUCE ROBERTS 31 - JIBSAIL
| Luff | * 34.22 ft - (10430 mm) |
|---|---|
| Foot | * 17.21 ft - (5246 mm) |
| Leech | * 29.73 ft - (9062 mm) |
| Percentage LP | * 115 % |
| Length Perpendicular | * 14.95 ft - (4557 mm) |
| Deck Angle | * 11.99 ° |
| Area | * 255.82 ft² |
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BRUCE ROBERTS 31 - GENOA
| Luff | * 40.63 ft - (12384 mm) |
|---|---|
| Foot | * 20.99 ft - (6398 mm) |
| Leech | * 38.21 ft - (11646 mm) |
| Percentage LP | * 150 % |
| Length Perpendicular | * 19.5 ft - (5944 mm) |
| Deck Angle | * 4.03 ° |
| Area | * 396.12 ft² |
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BRUCE ROBERTS 31 - ASYMMETRICAL
| Luff | * 40.63 ft - (12384 mm) |
|---|---|
| Foot | * 21.45 ft - (6538 mm) |
| Leech | * 37.38 ft - (11393 mm) |
| Perc LP | * 165 % |
| Area | * 654 ft² |
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BRUCE ROBERTS 31 - SPINNAKER
| Stays | * 40.63 ft - (12384 mm) |
|---|---|
| MidGirth | * 23.4 ft - (7132 mm) |
| Foot | * 23.4 ft - (7132 mm) |
| Perc LP | * 180 % |
| Area | * 808 ft² |
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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.