1. GENERAL

1.1 The Contender is a one-design single-handed trapeze boat.

1.2 The official language of the class is English and in the event of dispute over interpretation the English text shall prevail.

1.3 These Rules are complimentary to the plans and measurement form. Any interpretation shall be made by the ISAF which may consult the International Contender Association (ICA).

1.4 In the event of discrepancy between these rules, the measurement form and/or the plans, the matter shall be referred to the ISAF.

1.5 Boats shall be built in accordance with the class rules and specifications.

1.6 In countries where there is no National Authority (NA), or the NA does not wish to administer the class, its functions as stated in these rules shall be carried out by the ICA or its delegated representatives (National Associations).

1.7 Neither the ISAF nor the ICA accept any legal responsibility in respect of these rules or any claim arising therefrom.

2.1 Professional builders of the Contender shall be only those licensed by the ISAF and boats or hull kits shall be built for sale only by these builders.

2.2 Application for a licence shall be made through a NA to the ISAF which will consult the ICA before granting any licence.

2.3 Bona fide amateur builders are permitted for wood construction only, and are limited to the construction and registration of one Contender per year, and this shall be for their own use and not immediate re-sale. If circumstances necessitate immediate re-sale, then permission for this action shall be obtained from the ICA or relevant NA.

3.1 The International Class Fee is determined by the ISAF and may annually be reviewed.

3.2 The ISAF is responsible for the collection and distribution of the International Class Fee.

3.3 The International Class Fee shall be payable by the builder on each boat built whether or not it is subsequently measured and registered. Payment shall be made direct to the ISAF which will issue an International Class Fee receipt and ISAF plaque. The International Class Fee receipt and plaque shall be delivered to the owner on the sale of the boat.

4.1 No boat is permitted to race in the class unless it has a valid Measurement Certificate and unless the owner is a member of a National Contender Association.

4.2 Each NA shall issue sail numbers which shall be consecutive starting from one and the number shall be preceded by the official national letters. A NA shall issue a sail number only on receipt of evidence that the International Class Fee has been paid.

4.3 The certificate is obtained as follows:

4.4 Change of ownership invalidates the certificate but shall not necessitate remeasurement. The new owner may apply to this NA for a new certificate, returning the old certificate together with any re-registration fee required and stating the necessary particulars. A certificate shall then be issued to the owner.

4.5 It is the owner's responsibility to ensure that his boat, its spars, sails, and equipment, comply with the class rules at all times and that alterations or replacements to the boat, spars, sails or equipment, do not invalidate the certificate.

4.6 Notwithstanding anything contained in these rules, the ISAF or NA shall have the power to refuse to grant a certificate to, or withdraw a certificate from, any boat.

4.7 The ICA shall obtain at regular intervals from each NA details of sail numbers and certificates issued, together with the names and addresses of the owners.

5.1 Only a measurer officially recognised by a NA shall measure a boat, its spars, sails and equipment and sign the declaration on the measurement form that it complies with the class rules.

5.2 Measurement tolerances are intended to allow for genuine building errors only and shall not be deliberately used to alter the design. The measurer shall report on the measurement form anything which he considers to be a departure from the intended nature and design of the boat, or to be against the general interest of the class, and a certificate may be refused, even if the specific requirements of the rules are satisfied.

5.3 A measurer shall not measure a boat, spars, sails or equipment owned or built by himself, or in which he is an interested party or has a vested interest.

5.4 Templates used for official measurement shall be supplied by the ISAF.

5.5 All boats, spars, sails and equipment shall comply with current rules and measurement form or with the corresponding rules applied to them at the time the original certificate was issued. Any alterations or replacements shall comply with the current rules.

5.6 New or substantially altered sails shall be measured by an official measurer who shall button, stamp or sign and date the sails near the tack.

5.7 All boats, spars, sails or equipment shall be liable to re-measurement at the discretion of the NA or race committee.

6.1 The hull shall carry the International Class Fee plaque fixed in a conspicuous position inside the cockpit.

6.2 The mainsail shall carry identification marks as indicated in rule 17(4).

6.3 All emblems, letters and numbers shall be of a durable material and securely attached.

7.2 Composite hull:

A composite hull comprising GRP hull shell with wooden cockpit and deck is permitted. The GRP hull shell shall be made in an official mould by a builder licensed by the ISAF and shall comply with these rules, in particular 7.1(ii) above. The deck and cockpit may be of amateur construction and shall comply with these rules, in particular 9(4).

7.3 A structure to withstand the stresses imposed by the mast, shrouds and forestay may be installed between the chainplates, mast step and keel, directly below the mast step and the forestay attachment point. This structure may be of metal but shall not contribute to the stiffness of the hull or deck other than at the points stated.

8.1 The length of the hull overall, excluding overlap of aft and forward deck, shall be 4875mm ±10mm, measured between perpendiculars.

8.2 The hull shall be measured according to the measurement diagram. There shall be no concavities in the hull form aft of station 4 in fore and aft direction parallel to the keel greater than 3mm between each station. The transom shall not curve more than 3mm concave or convex in any direction. There are metal templates for the stations 1, 2, 3, 5, 7, 8, the stem and the stern profile. The measurement stations shall be permanently marked at the keel and sheerline as shown on the measurement diagram ± 2mm. Station marks along the sheerline shall be adjusted, taking into account transom rake. The adjustment shall be made making the transom at right angles to the base line stringline. The hull section, stem profile and sheerline shall conform to the lines ± 8mm as per the International Contender Plans.

8.3 The transom shall be on the extreme aft end of the hull excluding overlap of the aft deck, and may rake forward or aft not more than 15mm measured between the top of the deck and the bottom of the hull skin.

8.4 A datum shall be established for measuring the keel rocker as shown on the measurement diagram. The profile shall conform to the dimensions shown ±7mm.

9.1 The cockpit and decking shall conform to the measurements shown on the measurement diagram with a tolerance of ±20mm. For boats first certificated before 1st March 1975, the cockpit depth may be measured either from the inner edge of the deck or from the sheerline and its depth shall be between 170mm and 210mm at section 3, between 183mm and 223mm at section 4, and between 195mm and 235mm at section 5. In this case the deck camber shall not be measured.

9.2 The camber of the deck measured at the foot of the mast position shall not exceed 70mm.

9.3 The cockpit shall only be drained through:

9.4 In the case of wooden construction the entire deck and cockpit surface shall be a minimum thickness of 6mm and the wood shall have an officially recognised specific gravity of not less than 0.5. The measurer may drill six random check holes, not more than 3mm in diameter, in the deck and cockpit to verify this thickness.

9.5 The centreboard case trunk may extend into the cockpit and shall be not more than 60mm high or 160mm wide.

9.6 A watertight bulkhead shall be fitted transversely at the fore and aft ends of the cockpit and longitudinal watertight bulkheads at the inboard end of the side decks. Vertical cockpit corners may be radiused to 200mm maximum and horizontal cockpit corners may be radiused to 68mm maximum.

9.7 A continuous rubbing strake 15mm to 40mm wide and 10mm to 40mm deep (measured vertically) shall be fitted at the sheerline and may also be fitted to all or part of the top of the transom.

10.1 The builder shall ensure that not less than 100kg of positive buoyancy is secured to the hull, one-third shall be located forward of section 5 and the remainder aft of section 5 distributed equally around the centreline. This buoyancy may be used as a structural member. Air space shall not be considered positive buoyancy.

10.2 Inspection holes shall be closed in a watertight manner with detachable covers capable of resisting dislodgement whenever the boat is afloat, capsized, or full of water, and shall be of sufficient size to enable secondary buoyancy to be inspected.

10.3 The measurer shall check that buoyancy compartments are watertight.

11.1 The centreboard shall conform with the shape shown on the measurement diagram ±8mm, and the thickness of the centreboard extending below the keel shall not exceed 26mm.

11.2 The pivot is optional so long as the centreboard may be completely retracted into the centreboard case without moving the pin. The point around which the centreboard pivots must be in a fixed position.

11.3 The centreboard when fully down shall extend not more than 1214mm below the keel.

11.4 The centreboard shall be constructed of wood and/or glass reinforced plastic. Carbon fibre stiffening is permitted.

11.5 The weight of the centreboard shall be not less than 3.5kg including all fixed fittings.

12.1 The rudder blade shall conform to the underwater profile as shown on the plan ±8mm.

12.2 The rudder blade when fully down shall extend not more than 905mm nor less than 805mm below a line at right angles to the transom at the keel.

12.3 The rudder blade shall be constructed of wood and/or glass reinforced plastic. Carbon fibre stiffening is permitted.

12.4 The weight of the rudder shall be not less than 3.0kg including tiller, stock and fixed fittings, bust excluding tiller extension.

31.1 The mast shall be constructed of inherently straight aluminium alloy extrusion(s) and shall be of constant external dimensions up to a band of no.3. All sections of the mast must be permanently fixed together. The overall fore and aft measurement of the mast, including the sail track, shall not be less than 50mm nor more than 75mm and athwartships shall not be less than 48mm nor more than 61mm.

13.2 The extrusion(s) may be tapered from above band no.3 and the sail track opened or cut away below a normally positioned sail entry point, but otherwise the shape shall not be altered.

13.3 The mast shall not rotate.

13.4 The mast shall be stepped on deck.

13.5 Measurement bands, not less than 10mm wide, shall be marked on the mast so that they are clearly discernible when racing as follows:

13.6 The rigging on the mast is optional except that the main shrouds, trapeze wires and forestay(s) or their extensions shall intersect the mast between the upper edge of band no.2 and the lower edge of band no.3. Spreaders or pulleys are not permitted to be attached to the forestay(s).

13.7 The weight of the mast shall be not less than 7kg, complete with fixed fittings, all rigging and trapeze wires.

13.8 The mast complete with all standing and running rigging and supported at the upper edge of band no.1 shall weigh not less than 3kg when it is weighted at band no.4. For the purpose of this measurement the halyard shall be in the sailing position and the standing rigging secured along the mast above band no.1.

13.9 The distance between the aft edge of the mast including the sailtrack or its extension at the deck and the aft side of the transom at the centreline (excluding the aft deck overlap) shall be not less than 3050mm nor more than 3250mm.

13.10 The mast step, shrouds, spreaders and forestay(s) shall not be adjusted while racing.

13.11 All standing rigging shall be circular in section and shall have no fairings. The diameter of the main shrouds and forestay(s) shall be not less than 2.3mm.

13.12 The mast shall be drilled near to the heel with a hole or holes with a minimum total area of 200mm², so constructed that any water is immediately drained after a capsize.

14.1 The main shrouds shall be connected to shroud plates, which shall be not less than 250mm abaft the after side of the mast. The shroud plates shall be attached to the outside of the hull.

14.2 The forestay(s) shall meet the centreline of the foredeck at a point 4300mm from the aft side of the transom at the centreline excluding the aft deck overlap.

14.3 No other stays or shrouds are allowed to be attached to the hull forward of the mast.

15.1 The boom shall be constructed of inherently straight aluminium alloy extrusion(s) and shall be of constant external dimension throughout its length, except the track may be cut away to a total length of 200mm with the band at the tack and/or clew to avoid fouling the sail cringle(s). The section may be cut away or tapered to accommodate tack and clew fittings.

15.2 The boom, excluding fittings, shall be able to pass through an 80mm diameter circle.

15.3 A measurement band, not less than 10mm wide, shall be marked on the boom so that it is clearly discernable when racing with its inner edge not more than 2700mm from the line of the aftside of the mast, including the sailtrack or its extension, with the boom attached to its gooseneck in the normal sailing position. The measurement shall be taken along the line of the top of the boom.

16.1 The hull in dry condition shall not weight not less than 83kg including all fixed fittings and a traveller strop, but excluding the centreboard and its retaining fittings. In case the compass is fixed to the hull the trade mark and type of the compass must be noted in the measurement certificate.

16.2 If the weight of the hull is less than 83kg lead correctors, total weight not exceeding 6kg, shall be equally divided and fastened at the fore and aft ends of the cockpit not more than 50mm below the deck to make up the correct weight. The weight and number of correctors shall be endorsed on the certificate.

16.3 Neither any essential fixed fittings, nor any correctors shall be removed or altered without the boat being re-weighed by a measurer.

17.1 Not more than two sails are permitted for use during an international race or principal event.

17.2 The sail shall be constructed and measured in accordance with the 1986 IYRU Sail Measurement Instructions, except as defined in these rules.

17.3 Non-woven sail materials are permitted.

17.4 The sail number, letter(s) and class emblem shall be placed as laid down in the Racing Rules of Sailing. The class emblem representing international code flag "C" shall be 300mm to 350mm high and 450mm to 500mm wide. The sail number and letter(s) shall be of the following minimum dimensions:

height 300mm

17.5 No part of the sail or headboard shall extend beyond the inner edge of the boom band and the lower edge of mast band no.4. No part of the luff shall extend below the upper edge of mast band no.1.

17.6 The dimension of the headboard in any direction shall not exceed 120mm.

17.7 Not more than five battens are permitted and shall divide the leech into approximately equal parts. The length of the batten pockets shall not exceed 1050mm. The upper side of the top batten pocket shall reach from the leech to the luff rope at a point not less than 1230mm from the top of the headboard measured along the luff with just sufficient tension to remove wrinkles adjacent to the luff.

17.8 The sail shall project not more than 5mm past the edge of a straight line joining the headboard, or ends of the batten pockets or clew eyelet.

17.9 The length of the leech shall not exceed 6100mm.

17.10 The leech of the mainsail shall in no place be concave when not under tension.

17.11 The total width of the mainsail shall be measured at quarter, half and three-quarter heights on the sail. Any hollows in the leech shall be bridged by straight lines. The distance from three-quarter luff point to three-quarter leech point, half luff to half leech point, quarter luff to quarter leech point, shall not exceed 1210mm, 2020mm and 2520mm respectively.

17.12 Double-luffed or loose footed sails are prohibited.

17.13 The sailmaker shall mark his serial number permanently on the sail.

The following equipment shall be carried while racing:

18.1 A lifejacket, or buoyancy vest, which shall be worn at all times, unless the sailing instructions provide otherwise.

18.2 A towing ring shall be fitted and positioned forward of the forestay fittings.

18.3 Trapeze harnesses which shall not exceed 5kg in weight and shall float.

19.1 Hiking aids and out-rigging devices, except for toe straps, trapeze gear and rubbing strake foot blocks, grips or loops.

19.2 Hydrofoils, outriggers, ballast, suction bailers, keel bands except in way of centreboard slot, bottom rubbing strakes, electric and electronic equipment, spray deflectors and any projection from the skin other than normal fittings.

19.3 Where it is prohibited to adjust any device or system during racing any modifying device or arrangement shall be seized or properly secured prior to the race.

20.1 There shall be one person on board when racing.

20.2 With reference to Racing Rule 22.3(a) the total weight of clothing and equipment worn or carried by a competitor, including any buoyancy apparatus and trapeze belt or harness, shall not be capable of exceeding 12kg (twelve) when weighed as provided in Appendix 10 of the Yacht Racing Rules. Clothing worn underneath drysuits shall be weighed in the condition it is in when the competitor arrives ashore.

Weight jackets are prohibited.

An anchor need be carried only when specifically prescribed in the sailing instructions.

1 Body Plan Sept 1970

6A Recommended GRP Construction Nov 1970

for guidance of licensed builders