F4 One

One Class. Pure Racing.

Class rules

Draft version 0.3, 21 October 2026.

A. General

A.1	Authority The class intends to apply for World Sailing class status. Until then the class association administers these rules.
A.2	Open manufacturer class Any manufacturer may build class equipment. An item may be used only if its model is on the Approved Equipment List and is built to the Class Specification.
A.3	Independent oversight Approval of models, inspection and protests about equipment are decided by the Technical Committee, which has an independent Chair and no brand majority.
A.4	Amendments The General Assembly votes on changes. Once the class has World Sailing status, World Sailing approves changes before they take effect.
A.5	Review cycle The Class Specification is reviewed every [2] years. Other changes are published at least [6] months before they take effect.

B. Approved equipment

B.1	Approved Equipment List The Technical Committee publishes the list of approved models: manufacturer, model, size, version and approval date.
B.2	Reference package The F4 package in sections D to F is the reference equipment. It is approved at launch and defines the sizes and limits. The F4 package also includes a board bag and foil covers.
B.3	Applying A manufacturer applies with a pre-production sample and technical data. The Technical Committee measures the sample and decides within [90] days, with written reasons for any refusal. A refusal may be appealed to the Executive Committee.
B.4	Frozen models An approved model is frozen. Changes to shape, layup or dimensions need new approval, and the model version is marked on the item.
B.5	Availability Each approved model must be on sale to any rider in the countries the manufacturer ships to, at a published price. Prototypes and one-off parts are not eligible.
B.6	Quality control Each year the Technical Committee buys items from retail stock and measures them against the Class Specification.
B.7	Identification Each item carries a class sticker with manufacturer, model and serial number, visible without taking the foil apart.
B.8	Equipment cycle The Class Specification is fixed for [4] years from each launch. Models approved in a cycle stay eligible for that cycle.

C. Conditions for racing

C.1	Crew One rider. No motor, battery or other power source.
C.2	Declaration At registration each rider declares the package: one board, one mast, one rear stabilizer, wings of 4.8 and 6.3 m² and front wings of 540 and 700 cm², all from the Approved Equipment List. Only declared items may be used.
C.3	Changes between races A rider may change wing or front wing between races from the declared items. The board, mast and rear stabilizer may not be changed after the first race.
C.4	Replacement A lost or broken item may be replaced with an approved item of the same type with Technical Committee approval.
C.5	Safety A helmet and a buoyancy aid are worn while racing.
C.6	Advertising In accordance with the World Sailing Advertising Code.

D. Board

D.1	Reference board The F4 R Board race board, 75 L.
D.2	Class size Approved boards are 75 L only, within the limits of the Class Specification. Each rider uses one board at an event.
D.3	Dimensions and weight Length, width, thickness, volume and minimum weight, with tolerances of [__].

E. Foil

E.1	Mast Reference: the F4 GP 106. Approved masts match its length, section and mounting limits.
E.2	Front wing Reference: the F4 Wahoo 540 and the Wahoo 700 (540 cm² and 700 cm²). Approved front wings fit the area, span and aspect limits of one of these two sizes.
E.3	Rear stabilizer Reference: the F4 150XS. Approved rear stabilizers fit its span and area limits, as in the Class Specification.
E.4	Fixed surfaces Wings have no flaps, moving surfaces, sensors or electronics.

F. Wing

F.1	Class sizes Double surface wings in two sizes: 4.8 and 6.3 m². Reference: the F4 Mya V4.
F.2	Area The area marked on the wing, with a tolerance of [__] %.
F.3	Attachments One leash attachment point as built. No attachment that stops the rider letting go.

G. Manufacturers

G.1	Conflicts of interest Members of the Technical Committee who work for a manufacturer do not take part in decisions on that manufacturer's models.
G.2	Inspection The Technical Committee may inspect production and re-measure items taken from retail stock.
G.3	Suspension The Technical Committee may suspend a model for a safety fault or a breach of its approval until the fault is cleared.
G.4	Fees Approval and annual fees are published and are the same for every manufacturer.