Irwin 31
Description
The Irwin 31 is a fiberglass masthead sloop designed by Ted Irwin and built by Irwin Yachts in St. Petersburg, Florida, primarily from 1967 to the early 1970s. It was one of the earliest models produced by Irwin Yachts, introduced shortly after the company's founding in 1966. Designed as an affordable coastal cruiser, the Irwin 31 targeted families and entry-level sailors seeking a blend of comfort, simplicity, and modest performance for weekend sailing or short coastal trips. It predates the later Citation series (like the Citation 31), offering a more traditional design with a focus on spacious interiors rather than racing pedigree. The boat is distinct from the Citation 31, with a narrower beam and simpler layout, and it’s better suited for protected waters like bays or lakes than offshore passages. Approximately 200-300 hulls were built, making it less common than later Irwin models.
Construction Details
| Designer | Ted Irwin |
|---|---|
| Builder | Irwin Yachts |
| Length | 31.000 ft |
| LOA | 31.080 ft |
| LWL | 22.250 ft |
| Beam | 9.580 ft |
| Displacement | 9600 lb |
| Max Draft | 7.500 ft |
| Min Draft | 3.330 ft |
The standard boat dimensions
| i | 37 ft |
|---|---|
| j | 12.08 ft |
| p | 32 ft |
| e | 14 ft |
| p2 | - |
| e2 | - |
| i2 | - |
| j2 | - |
| I | J | P | E | P2 | E2 | I2 | J2 |
|---|---|---|---|---|---|---|---|
| 37 ft | 12.08 ft | 32 ft | 14 ft | - | - | - | - |
Sails
| Sail Type | MAINSAIL |
|---|---|
| Luff | * 32 ft - (9754 mm) |
| Foot | * 14 ft - (4267 mm) |
| Leech | * 34.2 ft - (10424 mm) |
| Tack Angle | * 88 ° |
| Diagonal | * 34.48 ft - (10510 mm) |
| Head (inches) | * 6 in - (152 mm) |
| Area | * 230.97 ft² |
| Sail Type | JIBSAIL |
|---|---|
| Luff | * 31.14 ft - (9491 mm) |
| Foot | * 16.05 ft - (4892 mm) |
| Leech | * 26.95 ft - (8214 mm) |
| Percentage LP | * 114.98 % |
| Length Perpendicular | * 13.89 ft - (4234 mm) |
| Deck Angle | * 12 ° |
| Area | * 216.24 ft² |
| Sail Type | GENOA |
|---|---|
| Luff | * 36.98 ft - (11272 mm) |
| Foot | * 19.55 ft - (5959 mm) |
| Leech | * 34.74 ft - (10589 mm) |
| Percentage LP | * 150 % |
| Length Perpendicular | * 18.12 ft - (5523 mm) |
| Deck Angle | * 3.97 ° |
| Area | * 335.04 ft² |
| Sail Type | ASYMMETRICAL |
|---|---|
| Luff | * 36.98 ft - (11272 mm) |
| Foot | * 19.93 ft - (6075 mm) |
| Leech | * 34.02 ft - (10369 mm) |
| Perc LP | * 165 % |
| Area | * 553 ft² |
| Sail Type | SPINNAKER |
|---|---|
| Stays | * 36.98 ft - (11272 mm) |
| MidGirth | * 21.74 ft - (6626 mm) |
| Foot | * 21.74 ft - (6626 mm) |
| Perc LP | * 180 % |
| Area | * 683 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.