It is managed by the Royal Ocean Racing Club (RORC) in the United Kingdom through their dedicated Rating Office,[1] and the Union Nationale pour la Course au Large (UNCL) in France.
The production of yachts which were excessively light and beamy - what became the classic 'diamond' plan form of the IOR - was believed to impact safety, and was cited as a factor in the 1979 Fastnet race disaster.
It considers such features as asymmetric spinnakers, carbon masts, canting keels, and water ballast, all of which have been permitted for several years.
Boat classes/models for which IRC Standards have been set in terms of LH, overhangs, empty weight, beam and draft measurements only.
The British RORC and the French UNCL, who jointly developed the rule, saw it as a means to get the "average club sailor" involved in racing, in the hope that they would subsequently upgrade their boat to participate under the IOR rule, or possibly the IMS handicapping system if that became more established.
The rule was designed to favour heavy cruising boats with lower sail areas, dissuading more extreme racing yachts coming in to Channel Handicap.