The IOM Class

The International One Metre class was created by Jan Dejmo, with the support of Graham Bantock and the Permanent Committee of the ISAF-Radio Sailing Division, and adopted by ISAF-RSD in 1988.  The intent was to pull together a variety of "One metre" class rules from different countries, and provide for a common, restricted, inexpensive international class of stable, easily-built designs.  The result is the most popular RC racing yacht class in the world.

The class has enjoyed such success because competitive IOMs can be built by an ordinary modeller at home, and due to the class restrictions competitive boats remain competitive for a number of years.
 

IOM rules

The performance of a RC yacht depends on hull lenght, beam, displacement, sail area, bulb draft, ballast ratio and rig plan. The only parameter than can be freely changed is the beam, all others are restricted by the IOM class rules. Therefore it is primarily differing beams  and positions of maximum beam, which distinguish the different IOM designs.

In addition to performance factors, the class rules explicitly restrict certain materials and construction methods in order to keep the class inexpensive and able to be built by an amateur builder.  Radio control is restricted to two channels. Appendages and sails can be made of any material. A competitive boat can be built at home.