Rules & Measurement

Class Measurer

Racing of all classes of sailing boat under the Racing Rules of Sailing (RRS) and Equipment Rules of Sailing (ERS) is based on the assumption that each boat complies with its Class Rules, the Class Rules complementing the RRS-ERS by defining the boat and equipment that may be used. Normally it is necessary to measure the physical dimensions of a boat, its equipment and sails to establish if it complies with the Class Rules and this is the principal role of the “measurer”.

Measurers therefore play a fundamental role in the organization of sailboat racing, and their ability to apply the Class Rules correctly and accurately is essential. Equipment must be measured for certification before being used for racing, but it is normally inspected at events as well.

Sunfish Measurer:
Rob Eberle
Phone: (252) 670-1976

Sail Number Requirements

If you will be competing in any World Championship qualifying event, please be sure your sail numbers are compliant with our current class rule 3.6.5. To be fair for all competitors, provisions in the rule pertaining to size, shape, color and placement will be enforced. 

A hyperlink to the class diagram is attached here.

Here are the highlights for compliance:

  • For sails purchased after January 1, 2015:  sail numbers must comply with RRS Appendix G.1 as modified by our class rules. This means that minimum height of numbers is 300mm (11-13/16”), minimum space between numbers is 60mm (2-23/64”) and numbers must still be positioned as indicated in the class diagram centered beneath the Sunfish emblem.
  • For “older” sails purchased prior to January 1, 2015:  numbers may comply with RRS G.1 as described above or as previously allowed in our rules prior to the latest change in January 1, 2015. This allows for “older” sails to use 10-inch numbers. Details are in our class rule 3.6.5 which should be referred to for placement, spacing and other details.
  • For all sails regardless of when they were purchased:
    1. Numbers must be of the same color.
    2. On white colored sails, numbers must be dark and dense, preferably black. Dark blue is acceptable.
    3. On dark colored sails, numbers must be white.
    4. Numbers must be of uniform size and shape.
    5. Numbers must be placed as shown on the measurement diagram, centered beneath the Sunfish emblem (not biased out toward the leech), with numbers on the starboard side placed above the seam, numbers on the port side below the seam and numbers parallel to the seam.
    6. Numbers provided on World Championship sails are considered compliant.
  • Digital numbers:  as per a World Council vote in October, 2015, digital cut numbers are currently permitted.


Class Rules

All boats wishing to race and compete shall comply with the International Sunfish Class Rules. The current International Class Rules (Effective January 1, 2015) are published on the ISAF website and you should always refer to the ISAF website to ensure you have the latest version.  The International Sunfish Class measurement and sail diagrams are also available.

Challenges & Interpretations to Class Rules

Any questions or challenges relating to ISCA Class Rules (Bylaw 1) should be forwarded to the Chief Measurer for interpretation along with detailed photographs and any comments or reasoning. The Chief Measurer will make an interpretation of all challenges, post interpretations to the Class website and communicate his interpretations to the Advisory Council. All such interpretations made by the Chief Measurer shall be binding until approved, rejected or modified by the World Council, duly published to the members of ISCA on the Class website.

The following challenges and interpretations to the Class Rules are currently active:

Rule Challenge & Interpretation - AC #8

Rule Challenge & Interpretation - AC #7  

Rule Challenge & Interpretation - AC #6

Rule Challenge & Interpretation - AC #5 

Rule Challenge & Interpretation - AC #4 

Rule Challenge & Interpretation - AC #3 

Rule Challenge & Interpretation - AC #2 

Rule Challenge & Interpretation - AC #1