18ft Skiff Class Design rules
The 18-Footers Class was born in the 1890's to satisfy a need for a boat, which was within the means of the "average man" and would provide good competitive racing to attract public interest.
These rules have been framed to uphold this philosophy.
• To provide good, fair, close racing;
• To minimise the cost of competition;
• To produce an attractive vehicle for public entertainment;
• To provide enjoyment for all competitors and
• To encourage new recruits.
• To stabilise the class by restricting hull shape until the year 2008, but allowing all other rules to be reviewed year by year, so as to accommodate in particular carbon fibre masts, boom and wings as they become more cost effective.
In all cases of dispute, the intent and spirit of the Rules will take precedence.
1. Hull
A hull, deck and attached appendages may only be constructed to the International League design by a registered builder from a female mould from approved materials. No changes are allowed to be made to the hull shape other than required as part of routine maintenance or repair.
If in the opinion of the governing body an attempt has been made to vary the approved hull design the boat in question will not be approved or registered.
The all up dry weight will be 170 kg and includes the following;
(Hull rigged with the number one rig, sails, wings, rudder, fin & all sheets & equipment normally on board when sailing (but excluding spares, tools & non essential items). In Order to avoid unfair advantage gained by weight correctors being placed close to the center of the skiff, they are to be securely fastened in the following percentages of the total weight located as follows: 10% not aft of the forward face of the bowsprit, 60% with the centres of the correctors not aft of the mast centreline, 30% on the rudder frame with the centres of the correctors not forward of the aft most vertical face of the transom.
Approved materials from which hulls may be constructed are: Carbon Fibre, Nomex, Closed Cell Foam, E-Glass, R-Glass, Aramid, Spectra, Carbon Fibre, Polyester, Vinyl Ester, Epoxy Resin, Resin systems requiring a curing temperature in excess of 90°C are specifically prohibited.
Bowsprits may only extend a max of 750mm from the stem. The Jib position is to be a max of 600mm from the stem
With the exception of a wire or rod bobstay for the spinnaker pole, the bobstay may not join the stem any lower than 100mm or higher than 130mm above the keel line.
The bob stay shall be a maximum width of 130mm and be parallel sided
The Chain Plates shall be a maximum width of 1810mm and positioned on the front wing mount.
2. Wings
Maximum overall horizontal width of all extensions, wings, planks or any other appendages (specifically excluding tiller extensions) measured in the most horizontal position is not to exceed 2,135m (7ft) from the centreline
Wings shallbe constructed and attached to the hull in such a way that they are not capable of adding additional righting moment, from whatever sources, beyond their own weight, and the weight of the crew they support.
Wings shall be constructed from, up to and including 6000 series aluminium, GRP or composite materials
Their sectional shape shall be substantially circular/round tubing.
Wing joints may be constructed from any material
3. Decking and Buoyancy
Placement of buoyancy is optional.
4. Sails
Each boat shall only race with registered sails. Registered sails shall be indelibly numbered and recorded on their registration certificate. Each boat may have the following max. registered sails for any 12 month period.
• 2 Mainsails
• 2 Jibs
• 2 Spinnakers
A boat attending a championship event in another hemisphere from its normal home continent shall be allowed to replace 2 sails.
One set of reef points will be permitted in the smallest mainsail.
Mainsails, Headsails (Jibs) and Spinnakers may only be constructed from approved materials
Approved materials from which Mainsails and Headsails (Jibs) may be constructed are: Mylar, Dacron, Aramid, Carbon fibre, and Spectra. A minimum weight of 154 grams per square metre applies to all approved materials.
Approved materials from which Spinnakers may be constructed are: HTS, 30-30, Trilite, Dynalite, and 0.9oz Silicone Coated Polyester. A minimum weight of 38 grams per square meter applies to all approved material.
5. Masts
At registration day each boat shall have indelibly numbered and recorded the masts in use at that time.
The masts shall be constructed from, up to and including 6000 series aluminium, GRP or composite materials
(1) Each boat may have a maximum of two (2) masts.
Each mast will be of fixed length and each mast will have a maximum height, which will be measured from the sheerline at the mast step:
• No. 1 10,225m (33ft 7in)
• No. 2 9,200m (30ft 2in)
Alternately
(2) Each boat may have 1 mast adjustable to two height positions .
6. Booms
The Boom shall be constructed from, up to and including 6000 Series Aluminium. GRP or composite materials
A maximum of one (1) Boom shall be allowed.
7. Spinnaker Poles
The Spinnaker Pole may be constructed from, up to and including 6000 series aluminium, GRP and composite materials.
Only one (1) spinnaker pole shall be allowed.
Any pole has a maximum length of 3.8m (12ft 5in) from the stem.
8. Crew
There will be a minimum crew of three. The minimum age of any crew member will be 14 years.
9. Hydrofoils
There shall be no hydrofoils allowed.
10. Centreboards & Rudders
A maximum of one (1) centreboard and one (1) rudder may be used.
No foil(s) may extend more than 1.6m (5ft 3in) below the keel.
Centreboards and rudders may only be constructed from approved materials, and out of an approved mould. No changes are allowed to be made to their shape other than required as part of routine maintenance or repair.
Approved materials from which Centreboards and Rudders may be constructed are: Closed Cell Foam, E-Glass, S-Glass, R-Glass, Aramid, Spectra, Carbon Fibre, Polyester, Vinyl Ester, Epoxy Resin. Resin systems requiring a curing temperature in excess of 90°C are specifically prohibited.
11. Rigging, Fittings
Titanium, or similar materials, are not permitted in rigging, fittings or fastenings. Rigging wires supporting mast and spinnaker pole will only be made from Stainless Steel.
12. Rule Exemptions
Intentionally left blank
13. Rules Compliance
It is the skippers and owners responsibility to ensure that their skiff complies with the rules at all times.
The Governing Body or its approved representative acting on behalf of the Governing Body, is responsible to ensure compliance with these rules.
Skipper/owner must make the skiff available for scrutineering at the request of the Governing Body or its approved representative.
14. Alterations & Exceptions to the 2005-2008 ISAF Rules
Alterations & Exceptions to the 2005-2008 ISAF Racing Rules of Sailing and corresponding National Rules
a. Rule 51 (Moving Ballast) is not applicable.
b. Rule 54 (forestay and headsail tacks) is not applicable.
c. Appendix J. The maximum weight of clothing and equipment is 10kg per person
Definitions
1. Hull
That integral part of the boat constructed so as to provide buoyancy, by the containment of air, or the partial or complete exclusion /displacement) of water. Specifically excluded are spinnaker poles, bowsprits, wings, centreboardand rudder fittings.
2. Gunwale
The points at which the plane of the outside of the hull skin, or its extension, would or does, meet the plane of the top of the deck or its extension.
3. Outer Gunwale
The outer-most edge of the hull and deck excluding removable appendages.
4. Stem
The most forward extremity of the hull.
5. Deck
A two dimensional (2D) surface, (or near 2D surface, allowing for the sheer of the gunwale), real or imaginary, that as or would have the effect of forming a lid for the skin.
6. Transom
A surface at the aft extremity of the hull.
7. Skin
Continuous outer layer of the hull, which below the waterline, when afloat, is in contact with the water. The skin includes the surfaces above the waterline extending there from to the gunwale.
8. Mast
Integral structure supporting, and/or forming whole or part of the sails, in vertical dimension. For the purposes of the restrictions of Rules 8 and 9, a sail comprised entirely of the mast shall be regarded as a mainsail and mast.
9. Mainsail
The sail aft of the mast
10. Head Sail (Jib)
A sail set with its luff in front of the mast: not permitted to be lowered while racing
11. Spinnaker
Any other sail set during a race.
12. Bowsprits
A bowsprit is a structure extending in front of the stem, which is used to support the tack of the jib and may support the spinnaker pole/bowsprit.
13. Spinnaker Pole
A spinnaker pole is a structure which is used for the purpose of supporting the tack of the spinnaker in a substantially horizontal manner away from the mast. It is measured as a separate hull extension
14. Hydrofoils
Devices comprising surfaces attached directly or indirectly to the hull; and which are designed to provide a level of vertical lift force that has the intent of reducing the immersion or drag of the hull while sailing
15. Wings
Wings are any structure, that extend beyond the gunwale in an outward direction, which are attached to the hull, and whose principle purpose is to increase righting moment by moving the crew outward
16. Registration Date
On this date a boat shall have registered.
1. Hull (including weighing)
2. Sails
3. Masts
4. Boom
5. Spinnaker pole
6. Centreboard and rudder
17. Measurements
Points of reference:
For the purpose of these rules, and the directions herein, the word vertical shall refer to the direction perpendicular to both the design waterline and the plane of the gunwales. Upward shall refer to the vertical direction away from the waterline and toward the deck.
Outward shall refer to a position extending furthest from the centreline of the hull in a horizontal plane.
18. Fittings
Fittings and other hull attachments that are for the purpose of attaching or supporting fittings, may be excluded from measurement, provided that in the measurers opinion such fittings/attachments do not outwardly flaunt the rules, that they do not affect the skiff’s hydrodynamic performance, and that they are functional.
19. New vs. Repair
A sail, mast, hull or any other item mentioned in these rules will be deemed new if more than 25% of its original area, volume or weight is replaced or altered.
Any alterations and/or repairs to any registered item (i.e. sails, masts, etc.) or repairs to the hull must only be done with written permission of the Governing Body, or its approved representative.
20. The International 18ft Skiff Association is the governing body.
Directives
1. All rules are originally written in English, in case of interpretation dispute, the accompanying definitions and the common (English) usage will apply. In the case of inconsistency, the definitions will prevail.
2. No artificial distortion, whether fairing, bumps, hollows or other localised discontinuity which would effect the approved hull shape are allowed
3. The Governing Body, or its approved representative has absolute discretionary powers to withhold a Measurement Certificate until he/she is satisfied, through observing sailing or such other method deemed appropriate, that any boat submitted for measurement complies with the spirit and letter of the rules.
4. Instructions to intended builders:
Builders intending to construct boats for measurement under these Rules are advised to submit details to the Governing Body, or its approved representative, any feature which may impinge upon the spirit or letter of these Rules. Upon submission of full drawings and explanations, a confidential advisory ruling may be obtained without obligation.
5. Figures in brackets are only for convenience. Metric measurements are binding