12 Metre
international racing sailing class
The 12 Metre class is a rating class for racing sailboats that are designed to the International rule. It enables fair competition between boats that rate in the class whilst retaining the freedom to experiment with the details of their designs. The designation "12 Metre" does not refer to any single measurement on the boat, and is not referencing the vessels overall length, rather, measures the sum of the components directed by the formula which governs design and construction parameters. Typically 12 Metre class boats range from 65 to 75 feet (about 20 to 23 m) in length overall; they are most often sloop-rigged, with masts roughly 85 feet (26 m) tall.
The first 12 Metres were built in 1907. The 12 Metre class was used in the Olympic Games of 1908, 1912 and 1920 but few boats participated in these events. The 12 Metre class boats are best known as the boat design used in the America's Cup from 1958 to 1987.
Competitiveness between boats in the class is maintained by requiring the boats to be in compliance with the 12 Metre formula. Designers and builders are required to take into account such things as the sail area, the boat length at the waterline and the boat girth (the measurement around the boat from one sideboard, under the keel, and then over the top on the opposite side back to the original side). The measurements are then weighted in the formula.
Begin with the source’s own compact description: “12 Metre” is international racing sailing class. The dossier treats that line as a proposition to test through Metre, international and racing, not as a finished interpretation.
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Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Sep 3, 2026. The linked authority identifier is Q8658. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1907, 1908, 1912 and 1920.
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This entry incorporates text from “12 Metre” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.