IMCA Constitution & Rules

General Class Information

Official IMCA Constitution

The current IMCA Constitution is available here: IMCA Constitution - 14 November 1998 (Word document 30Kb)

Official IMCA Rules

The current International Moth Class rules are available here: IMCA Rules (PDF file - 13Kb)

ISAF Sail Area Measurement Manual (1977)

Files are PNG and approximately 20Kb each.

IMCA Sail Area Calculation Spreadsheet

The following is an MS Excel Spreadsheet that can be used to calculate the area of a Moth sail.

• Sail Area Spreadsheet (14Kb)

Official IMCA Rule Interpretations to Current Class Issues

December 2002 - Revised Interpretation and Explanation

A vote and poll of the member associations during 2002 and a decision made by the IMCA Executive, has decided that the use of wing buoyancy is appropriate so long as the moth is not sailed as a multihull. It was also decided that wing mounted hydrofoils provided multihull like stability and were to be in breach of the no multihull rule. The following interpretations are issued to allow use of the existing rules to enforce these decisions.

A. Wing Buoyancy - There is no limitation to the amount, type or shape of buoyancy contained in the wings, trampolines or wing tubes of an International Moth (other than that defined in rule 6.3.i), however the boat must NOT be sailed with the wing bar floatation on the waters surface for more than is required to stabilise the boat back to a vertical position, otherwise this is in breach of rule 6.3.i.

B. Hydrofoils - Wing mounted hydrofoils are in breach of rule 6.3.i whilst sailing on the foils. This interpretation is effective as of 1 December 2003.

C. General Explanation covering wing mounted buoyancy and foils: The existing longitudinal air gap rule 6.3.iii is deemed to apply to all centerboards, lee boards, foils, wings, hulls and floats installed as for racing, and is to be assessed with the boat floating as set out in the existing rule 6.3.ii.

D. Explanation applicable to conventional centerboards. Any centreboard when installed within the static waterline of the hull, is considered not to breach rule 6.3.iv.

E. Winged centerboards (in accordance with D. above) or winged rudders are NOT in breach of any IMCA rules.

Official International Moth Symbol

Download the official Moth symbol as prescribed in the IMCA rules and by ISAF: Corel Draw file Adobe Illustrator Version 8 Adobe Illustrator Version 9