International One Design
Description
The International One Design (IOD or “Inter”) is a 33 ft 4 in (10.16 m) classic one-design keelboat commissioned in 1936 by Cornelius Shields Sr. specifically to bring big-boat thrills and strict one-design racing to private owners at a reasonable cost, using the lines of Sigurd Herbern’s revolutionary Norwegian 6-Metre “Saga” as the starting point and adapting them into a Bermuda-rigged sloop with long overhangs, low freeboard, and a full keel drawing 5 ft 4 in (1.63 m). Built to exacting standards—originally in mahogany planking on oak frames (1936–1960s), later in cold-molded wood/epoxy and finally fiberglass (approved 2008)—every IOD is required to weigh exactly 7,100 lb. (3,221 kg) with 4,400 lb. of lead ballast, carrying about 436 ft² (40.5 m²) of sail on a tall wooden or aluminum spar. Crewed by 4–6 (often 5), the boat is famous for its exquisite balance, fingertip helm, and ability to plane downwind in 15+ knots while still pointing remarkably high upwind. Only about 200 hulls have ever been built, yet the class remains one of the most active and competitive classic fleets in the world, with strong centers in Northeast USA (Northeast Harbor ME, Fishers Island NY, Marblehead MA, Long Island Sound), Bermuda (where the class originated the famous King Edward VII Gold Cup match-racing event), Norway, Sweden, San Francisco, and the UK. Supported by the tightly run World Class Association (iodwca.com) that still mandates annual weighing and measurement, the IOD continues to deliver champagne sailing and some of the closest racing on the planet nearly 90 years after its launch—often described as “the most beautiful one-design ever drawn.”
Construction Details
| Designer | Bjarne Aas |
|---|---|
| Length | 33.000 ft |
| LOA | 33.160 ft |
| LWL | 21.420 ft |
| Beam | 6.750 ft |
| Displacement | 7100 lb |
| Ballast | 4400 lb |
| Max Draft | 5.160 ft |
| Year Built | 1936 |
The standard boat dimensions
| i | 29.30 ft |
|---|---|
| j | 8.30 ft |
| p | 38.80 ft |
| e | 16.30 ft |
| p2 | - |
| e2 | - |
| i2 | - |
| j2 | - |
| I | J | P | E | P2 | E2 | I2 | J2 |
|---|---|---|---|---|---|---|---|
| 29.30 ft | 8.30 ft | 38.80 ft | 16.30 ft | - | - | - | - |
Documents
Sails
International One Design - MAINSAIL
| Luff | 39.083 ft - (11912 mm) |
|---|---|
| Foot | 16.125 ft - (4915 mm) |
| Leech | * 38.55 ft - (11750 mm) |
| Tack Angle | * 77.18 ° |
| Diagonal | 38.83 ft - (11835 mm) |
| Head (inches) | 6 in - (152 mm) |
| Area | * 315.26 ft² |
| Edit in Calculator |
International One Design - JIBSAIL
| Luff | 26 ft - (7925 mm) |
|---|---|
| Foot | 9.83 ft - (2996 mm) |
| Leech | 24.5 ft - (7468 mm) |
| Length Perpendicular | * 9.25 ft - (2819 mm) |
| Area | * 120.3 ft² |
| Edit in Calculator |
International One Design - SPINNAKER
| Stays | 30 ft - (9144 mm) |
|---|---|
| MidGirth | 22 ft - (6706 mm) |
| Foot | 22 ft - (6706 mm) |
| Area | * 561 ft² |
| Edit in Calculator |
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.