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 Class symbol | |
.svg) | |
| Development | |
|---|---|
| Designer | Charles E. Nicholson (rule designer) |
| Year | 1949 (rule design) |
| Design | Development class |
| Name | International 5.5 Metre |
| Boat | |
| Crew | 3 |
| Draft | Maximum: 1.35 m (4 ft 5 in) |
| Hull | |
| Type | Monohull |
| Hull weight | Minimum: 1,700 kg (3,700 lb) Maximum: 2,000 kg (4,400 lb) |
| LOA | About: 9.5 m (31 ft) |
| Beam | Minimum: 1.92 m (6 ft 4 in) |
| Hull appendages | |
| Keel/board type | Fixed |
| Sails | |
| Spinnaker area | About: 50.0 m2 (538 sq ft) |
| Upwind sail area | Minimum: 26.5 m2 (285 sq ft) Maximum: 29.0 m2 (312 sq ft) |
| Former Olympic class | |
TheInternational 5.5 Metre class was created to yield a racingkeel boat that would give a sailing experience similar to that of theInternational 6 Metre Class but at a lower cost.
The main class regulation restricts a single quantity output from a formula involving the boat's rating lengthL, weight (expressed as a displacementD) and sail areaS; the regulation states that the output of this formula must not exceed 5.500 metres. There is considerable scope for variations in design while still meeting this restriction, and as a result, each 5.5 metre boat is unique.
If the design parameters of a proposed new boat result in a formula output exceeding 5.5 metres, then one or more of the parameters must be suitably adjusted. Performance data gained from testing models towed in a long water tank (referred to in yacht design as aShip model basin) can suggest optimal combinations of parameters.The 5.5. metre rule is a variant of theInternational Rule (sailing) established in 1907. The 5.5. is therefore closely related to larger metre boats such as the6mR,8mR and the12mR.
Since 2010, the 5.5 Metre is one of the Vintage Yachting Classes at theVintage Yachting Games.
The 5.5-metre class was a redesign of the 6-metre class byCharles E. Nicholson in 1937. The first boats conforming to the 5.5-metre rule were built in 1949. There had been an earlier attempt to build a cheaper alternative to the Sixes. In 1929, the 5-metre class was established by the French "Union de Societes Nautique Francaise" and was accepted in London. It achieved a position as the smallest new international metre class, and some hundred boats were built. Nevertheless, the 5 metre never managed to achieve an Olympic status. The 5.5-metre class replaced it quickly and was raced in the1952 Summer Olympics inHelsinki for the first time. TheScandinavian Gold Cup has competed with 5.5m boats since 1953. 5.5 metre boats replaced the International 6-metre at the1956 Olympic Games inMelbourne,Australia. The 5.5 metre participation in the Olympic sailing events continued at the1960 and the1964 Olympic Games. During the 1960s; however, it began to draw similar criticism as the preceding six-metre class - namely, increasing costs - and the boat lost Olympic status after the1968 Olympic Games, due to excessive design and building costs of one-off boats, marking the end of development class keel boats in Olympic regattas. However, the class remained active thereafter, and 5.5-metre boats are still very actively raced.
The measurement formula is given in the2006 International Five Point Five Metre Rating Rules:
where
| Rank | Nation | Gold | Silver | Bronze | Total |
|---|---|---|---|---|---|
| 1 |  Sweden (SWE) | 2 | 1 | 1 | 4 |
| 2 |  United States (USA) | 2 | 0 | 2 | 4 |
| 3 |  Australia (AUS) | 1 | 0 | 0 | 1 |
| 4 |  Great Britain (GBR) | 0 | 1 | 1 | 2 |
 Switzerland (SUI) | 0 | 1 | 1 | 2 | |
| 6 |  Denmark (DEN) | 0 | 1 | 0 | 1 |
 Norway (NOR) | 0 | 1 | 0 | 1 | |
| Totals (7 entries) | 5 | 5 | 5 | 15 | |
| Rank | Nation | Gold | Silver | Bronze | Total |
|---|---|---|---|---|---|
| 1 |  Finland (FIN) | 1 | 0 | 0 | 1 |
| 2 |  Germany (GER) | 0 | 1 | 0 | 1 |
| 3 |  France (FRA) | 0 | 0 | 1 | 1 |
| Totals (3 entries) | 1 | 1 | 1 | 3 | |
| Rank | Nation | Gold | Silver | Bronze | Total |
|---|---|---|---|---|---|
| 1 |  United States (USA) | 1 | 0 | 0 | 1 |
| 2 |  Canada (CAN) | 0 | 1 | 0 | 1 |
| 3 |  Ecuador (ECU) | 0 | 0 | 1 | 1 |
| Totals (3 entries) | 1 | 1 | 1 | 3 | |
| Event | Gold | Silver | Bronze |
|---|---|---|---|
| 1959 Chicago | United States | Canada | Ecuador |
| Rank | Nation | Gold | Silver | Bronze | Total |
|---|---|---|---|---|---|
| 1 |  Switzerland (SUI) | 7 | 4 | 7 | 18 |
| 2 | Norway (NOR) | 2 | 2 | 0 | 4 |
| 3 | United States (USA) | 1 | 0 | 1 | 2 |
| 4 | Great Britain (GBR) | 0 | 1 | 1 | 2 |
| 5 | France (FRA) | 0 | 1 | 0 | 1 |
 Soviet Union (URS) | 0 | 1 | 0 | 1 | |
| Totals (6 entries) | 10 | 9 | 9 | 28 | |
 |
The object of the International 5.5 Metre Class Association is to promote and develop 5.5 Metre racing throughout the World. The first President of the association wasMr. Owen Aisher.[9]
Since the development of the class spanned more than half a century, the early boats are not competitive in racing against the modern designs. Therefore, the association made, in 2007, divisions in the class based upon the age of the boat:[10]
During major races, there are separate trophies per fleet; however, if a classic fleet boat beats the modern fleet, the classic fleet boat wins the modern fleet trophy.
