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Yacht Design

A new 9,50m long open class for monohulls

Presentation of the characteristics • Download the rules in english

samedi 27 janvier 2007Christophe Guigueno

Jean-Marie Vidal (past Figaro race winner and mini sailor) is launching a new open class for monohulls. Minis are too smalls for cruising, Class 40 is quite expensive, these are the first two ideas for the launching of the new rule which will define an 9,50 meters long open class for racing-cruising monohuls. Extracts of the rules…

BASIC RULES : This rule applies to monohull sailing yachts, with the aim of racing offshore in real time. A monohull is a boat with a single flotation plane at rest or under sail, whose hull depth in any transversal section shall not decrease towards the centre-line.

Current ISAF rules (RCV, ERS & OSR) apply
- The Classe 9.50 monohull Class Rules are the open type set out in Paragraph C.3.3 of the ERS (Rules of Equipment for Sailing boats), meaning that anything that is not expressly forbidden, limited or enforced, is authorized.
- The Class official language is French.
- The Class 9.50 monohulls are aimed to coastal and offshore racing.


- The class must respect the conditions set out in Category C of the Publicity Code of the ISAF Ruling (Chapter IV ; 20).
- Routing is forbidden while racing.


- The boat must comply with all aspects of the ‘NF EN ISO 12217 Small Creaft – Stability and Buoyancy Assessment and Categorisation – part 2 : Sailing boats of hull length greater or equal to 6 m’ for design Category A, as well as the requirements set out in the OSR for Sailing Category 1. In the event of a conflict between the OSR and the NF EN ISO 12217 standard, the latter will prevail.

The skipper will provide either a compliance certification to the standard issued by the yard, or a solemn declaration for the custom built leisure crafts (appendix 224-A.1 of the new division 224)


- The appendages are limited to one keel, fixed while sailing and two rudders (non lifting blades) maximum.
- Note : Canards and dagger-boards are forbidden.

102. RIG
- Canting and pivoting masts are forbidden
- Forestays, backstays, runners and shrouds (permanent or temporary) must be fixed to chain plates situated inside the natural intersection of hull and deck. A tolerance of 20 mm is allowed for attached chainplates
- Deck spreaders are forbidden

103. SAILS
- The total number of sails taken onboard is limited to 7, including a storm-jib.
- Any material other than woven or laminated polyester is forbidden in the manufacture of the mainsail and jibs. Any material other than Nylon is forbidden in the manufacture of the spinnakers.
- The mainsail must display the Classe 9.50 logo, which must be obtained exclusively from the Classe 9.50 committee.


In addition to the OSR Cat 1 rules, there must be onboard :
- 1 chart table, permanently fixed
- A minimum of 4 bunks, prmanently fixed
- 2 tanks of a minimum capacity of 50 L. for fresh water. They must be permanently fixed and the top them must not be higher than 10 cm above the DWL
- 1 tanks of a minimum capacity of 50L. for fuel, permanently fixed.


- Electrical power is delivered through several batteries of a minimum global capacity of 200 A/h in 12 V for servitude batteries and of 40 A/h for the engine batteries.
- These batteries must be watertight. By watertight, one means : of which the acid cannot leak immediately in a horizontal position. They must be fixed for the entire competition, in such a way that they cannot move, whatever the trim of the boat.
- These batteries must be electrolytic using lead.


- The dimensions that must be measured in compliance with the NF EN ISO 8666 standard are indicated by the name EN/ISO 8666 followed by the relevant chapter.

- The boat loading condition for the measurement trim is the Light Craft Condition LCC (in conformity with 6.3 of the EN ISO 8666 standard and 3.5.1 of the EN ISO12217-2 standard) excluding the mooring gear (anchor, chain and mooring line) and the loose external equipment (fenders, warps, mooring lines), the life raft and the sails.

202. HULL LENGTH (Lh) : ( EN/ ISO 8666 §5. 2. 2)
- The hull length must not exceed 9,50 m.
- Reminder : This measurement does not include rudders and their fittings, bobstay fittings, devoid of devices designed to lengthen the waterline, nor pulpits and pushpits, solar panels and wind vane autopilots.

203. MAXIMUM BEAM (Bmax) : ( EN/ I SO 8666 §5. 3. 2)
- The maximum beam must not exceed 3,75 m.

204. MAXIMUM DRAFT (Tmax) : ( EN/ I SO 8666 §45. 4. 4. 1)
- The maximum draft must not exceed 2,40 m (boat in measurement trim §201)

- The mean freeboard must not exceed 1 m.
- The mean freeboard is obtained by dividing the vertical projected area of the topside of the hull (up to the gunwale line as defined in EN ISO 8666 and interpreting the ERS for rounded gunwale) by the hull length (Lh).

206. DISPLACEMENT The mass of the must not be less than 2.600 kgs . This mass is established for a boat in loading conditions §201.

- 207.01 Solid ballast : Reminder : See OSR §2 03 2a
- 207.02 Liquid ballast : The maximum authorised volume of liquid ballast is 900 L. to be distributed symmetrically (450 L. on each side). In case of Bmax <than 3.75, the total volume must stay smaller to ((900 / Bmax) X 3,75 ), to be distributed symmetrically. (eg : if Bmax=3.60, ((900 / 3.60) x 3.75 = 937.5 litres)

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 permanently tied close by.

208. MAST (Highest point)
- A band measuring a minimum of 25mm in width in a contrasting colour must be affixed around the top of the mast. The lower part of this band will be situated at a maximum height satisfying the two following measures : Hmast=(Hmain+Hjibc+Hspin)/3< than 15m50, given that the maximum height of the mast must never exceed 16.50 m above the water surface. Hmain, Hjib, Hspin are the heights of the mainsail, jib and spinnaker halyard sheaves, taken from the waterline. All measures taken from the waterline apply for the boat in loading condition §201. No point of any set sail may be situated above the lower part of this band. In the absence of such a band, the high point will be the highest point of the tube making up the mast.

209. BOOM
- The aftermost part of the boom must be further aft of the aftermost point used to determine the Lh, whatever the trim of the mainsail.

- Once in position, the forward extremity of the bowsprit must not exceed the forward extremity of the boat used to determine Lh by more than 3.00 m

- Once in position, the forward extremity of the spinnaker pole must not exceed the forward extremity of the boat used to determine Lh by more than 2.00 m

212. SAILS
- The sail area is free providing it respects the limitations of the box (mast height, boom length, pole/sprit length). The race number must be worn on each side of the mainsails, jibs, genoas and storm-jib.
- Additionally the mainsail must also display the national letters and the logo of the Class, available from the Class. National letters must be above the race number and starboard letters above the port side ones. Dimensions of the numbers and letters are defined by the International ISAF rules (RCV 2005-2008, Appendix G, Article G1.2)


English rules

Jauge en français

For more information about the Classe 9m50, contact JM Vidal.

A Class 9.50 from FoX Technology

- Longueur : 9.50 m
- Largeur : 3.65 m
- Tirant d’eau : 2.40 m
- Déplacement : 2600 kg
- Tirant d’air : 15.50 m
- Surface de voile au près : environ 80 m2
- Surface de voile max au portant : environ 170 m2
- Ballasts : 925 L. répartis symétriquement
- Site web :

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