ILCA Class Rules


In this section you will find the ILCA Class Rules, covered in By-Law 1of the ILCA constitution.

You can either download the ILCA Class rules  as a pdf, browse sections of the rules online or use the search facility to find information on specific items. You can use the links below to navigate between sections of the guide.

  • Part One explains the Fundamental Class Rule which covers the philosophy and any item not specifically written into the rules.
  • Part Two tells you what you must do to have a legal boat.
  • Part Three details a few optional changes and additions you can make.
  • Part Four details options for the Laser Radial and the Laser 4.7 rig
  • Part Five explains what kind of approval is required to make changes to the Class Rules

The principle of the Laser Class Rules is that no changes to the boat are allowed unless they are specifically permitted by the class rules. The English text of the Laser Class Rules shall govern.

These Class Rules are valid from 1st February 2015. Cancels all previous rules and interpretations.


01 January 2016: 

Rule 4(f) National Letters: updated wording with instructions for positioning of letters on new MKII sail.

01 February 2015: 

Rule 3(h)i sentence added: A splice that does not extend through the nearest traveller eye may be used at the non-free end.

Rule 4 new rule added. 4(h) NATIONAL FLAG.  If required by the Notice of Race and the Sailing Instructions, a national flag with a nominal size of 567 x 337 mm shall be applied to both sides of the mainsail. For the Standard and Radial sails, flags shall be positioned such that the aft edge of the flag is within 100 and 150 mm of the leech and between the sail numbers and the batten pocket below the sail numbers. The flag shall be approximately parallel with the sail numbers and letters and shall not touch the numbers. For the 4.7 sail, the flag shall be positioned within 100 and 150 mm of the leech but below and within 50 mm of the bottom batten pocket. The flag shall be printed on separate material applied to the sail. The use of permanent ink pens or similar to make a national flag is forbidden. The national flag shall correspond to the national letters. 

Rule 10 modified: Advertising, including competitor advertising, is permitted in accordance with ISAF regulation 20 – Advertising code; except that the sail window shall be kept free of advertising or other graphic material. 

Rule 14(d) sentence added: Vertical cuts are allowed in the material to allow the material to conform to the shape of the centreboard case.

Rule 15 new rule added. 15(k): Padding of uniform thickness may be used in the gap between the rudder blade and rudder head. This padding must cover completely the part of the rudder blade that comes in contact with the rudder head. The thickness of the rudder blade plus the padding must not exceed 20.3mm. 

Rule 18 new rule added. 18(c): Traveller and Boom mounted mainsheet blocks may be replaced with the "Builder Supplied" blocks shown in the photo. 

Rule 26(c) modified: Preventative maintenance includes the replacement of fasteners (screws, bolts, nuts, washers and rivets) provide the replacement does not alter the function of the fitting. The tolerances of the Measurement Diagrams shall not be used to alter the position of fittings. In addition the reversing of spars is permitted if the fittings are replaced in accordance with the Measurement Diagrams. Any holes in the top section of the mast shall be permanently sealed with a rivet or similar to maintain the buoyancy of the mast.

23 April 2013: 

Fundamental Rule modified: Clarification that Lasers shall be built by ISAF and ILCA approved manufacturers in adherence to the Construction Manual. 

Definition of Builder modified: Modified to conform to current ISAF agreements. 

1 January 2012:

Rule 3 (c) i modified: The mainsheet shall be a single line, and be attached to the becket of the aft boom block, and then passed through the traveller block, the aft boom block, boom eye strap, forward boom block and the mainsheet block. After the mainsheet block it shall be knotted, or tied, so that the end of the mainsheet cannot pull through the mainsheet block. The mainsheet shall not be controlled aft of the forward boom block except to facilitate a tack or gybe.

Rule 3 (c) ii modified: The tail of the mainsheet may also be knotted or tied to either the base of the mainsheet block, the hiking strap, the hiking strap support line, or the hiking strap shock cord. This option, if used, satisfies the knotting requirement in 3(c)i.

Rule 22 modified:

Compass, Electronic Equipment and Timing Devices

(a) One compass is permitted mounted on any part of the deck or the cockpit, provided that the hull cavity is not pierced by anything other than the fasteners. Compasses shall not be fitted to inspection ports. Electronic and digital compasses are prohibited (see exception in part d).

(b) Any use of electronic equipment not specifically allowed in the rules is prohibited unless modified in the sailing instructions.

(c) Timing devices are permitted.

(d) A timing device that includes an electronic compass is permitted as long as it is worn on the wrist.

Rule 14 (f) modified: A tie line or shock cord shall be attached to the small hole in the upper forward corner of the centreboard, and any of the bow eye, the cunningham fairlead, the “Builder Supplied” deck block fitting and the mast to prevent loss of the centreboard in event of a capsize. The tie line or shock cord may be looped around the bow, but shall not be attached to the gunwale. Attachment can be by knots or loops in the shock cord, and/or tie lines, shackles, clips, hooks or eyes. When the shock cord is attached to the bow eye it may also pass through an attachment to the “Builder Supplied” deck block fitting or the cunningham fairlead.

Rule 28 and Rule 29 modified: For the purposes of RRS 43.1(b) the maximum total weight of competitors clothing and equipment shall be 9Kg for Radial and 8Kg for 4.7


1 January 2011:

Rule 3(e)ii modified: The cunningham control line shall be securely attached to any of the mast, gooseneck, mast tang, swivel or shackle that may be used to attach the vang cleat block to the mast tang, the cunningham attachment point on the "Builder Supplied" vang cleating fitting or the becket of an optional becket block fixed on the cunningham attachment point on the "Builder Supplied" vang.

Rule 3(f)vi modified: A shock cord for use as an inhaul may be attached between the outhaul cleat and clew of the sail, the clew tie down, the optional block at the clew, the quick release system or through the clew of the sail and to an optional block in the primary control line.

Sentence added to Rule 3(g)i: An additional outhaul extension tie line may be added between the clew of the sail and the outhaul or the quick release system.

Rule 21 modified: Clips, ties or bags to stow or secure safety or other equipment may be used on the deck, in the cockpit, around the mast or boom.

Rule 24 modified: Tape and Line. The use of flexible adhesive tape or similar or line is permitted to secure shackle pins and clips, and to bind sheets, control lines and rigging, except that tape or line shall not be used to construct new fittings or modify the function of existing fittings.

New Rule 27: The sail may be reefed by rolling the sail around the mast 1 or 2 times.