This page is totally about the design rules, download the rules for free from the Classemini.com site. See page Ratios if you want to know about Ratios and Performance and more statistics of the MT.
The Serpentaire The Wylie design The Berret design The Finot design
A brief development history:
In the first race in 1977 the boats were production or home built cruisers like the Serpentaire, winner of the first race. Because
the lack of suitable designs some sailors cut the bow away from boats to qualify the length limit.
The Open 6.5 class is a playground for designers who see their product really tested, for sailors with a modest budget to attract attention or reaching their dream. And recently (2003) the top of the bill campaigns are devolping, result is a push for refinement. But they still get sometimes beaten by crapy boats with great sailors (Like Joschke, 2005-2006 on her Cape design beating a lot of new Manuards and others.). Top of insult is if you have an all tricked out carbon machine and you get passed by a polyester serie boat...
THE DESIGN RULES:
III - Hull Design
* The length of the hull must not exceed 6.50 metres. This dimension does not include rudders and their fixings, the fittings of the bowsprit bob stay (without devices intended to extend the length at waterline) as well as the solar panels, push pits, pulpits and wind vane pilot.
* The length of the hull is measured between the perpendicular of the bow and transom. The fore stays, the back stays, the shrouds (permanent or temporary) must be fixed inside the length of the hull..
* Bottom of keel to top of the highest sail = 14 metres maximum
* Max. draught : 2 metres, regardless of the angle of heel and the position of appendices or mobile appendices.
* The booms may not extend beyond the transom with the mainsail up at full hoist
* The cockpit floor must be 15 cm minimum above the waterline.
* Max. beam : 3 metres including mobile keels and masts and rigging.
* Ballast is allowed if they are fixed, located inside the hull and part of the
structure of the boat. The total volume of water ballast must not exceed 400 litres symmetrically displaced along the longitudinal axis of the boat. Their use must not compromise the ability of the boat to right itself. The vents for each ballast must be located on the deck and have a minimum inside diameter of 25 millimetres. Each vent must have a cap.
* Sails : The number of approved sails carried on board must not exceed eight (8). This must include a storm jib of maximum area 4m2, reef able to 2.5m2, and a try sail of 5m2 maximum area of a fluorescent colour and a minimum weight of 340 g/m2.
* Material Sails (EXPECT BIG CHANGE IN 2008 RULES)
The stability test is effected with the head of the mast at water level with full ballast on one side then on the other side.
Small angles stability :
The boat while empty except for batteries and the life raft, must not exceed a 10 degree heel angle in the most unfavourable ballast, mobile keel and mast configuration."so with a canting keel it means that how heavier the bulb or how more it cants the boat has to have more resistance against heel, a stiff (wide) boat is the result.