Sailboats

Sailboats use the power of the wind acting on sails to propel the boat. Model sailboats are typically controlled via a multi-channel radio transmitter in the hands of the operator with a corresponding receiver in the boat. By changing the position of the two joysticks on the transmitter signals are sent over two separate channels on a single radio frequency (assigned to the individual boat/operator). On the boat, the radio receiver is connected to two battery powered electric motors or servos. Signals from the radio transmitter are interpreted by the radio receiver and translated into instructions to change the position of the servos. One servo controls the position of both main and jib sails together (allowing the sails to be trimmed), the other the position of the rudder (allowing the boat to be steered).

 

Racing sailboats

Sails model sail boats is governed by the same ISAF (International Sailing Federation) Racing Rules of Sailing that are used for full sized crewed sailing boats (with the inclusion of Appendix E, that introduces special rules to govern the radio-controlled sport).
There are four international classes of radio sailing boats recognized by the ISAF-Radio Sailing Division: (from smallest to largest).

- International One Metre (IOM)
    The IOM class rules specify a monohull of maximum length 1000 mm, with            

    maximum draught 420 mm. There is a minimum weight of 4000 g, which makes

    homebuilding of competitive boats possible. The IOM has three one-design rigs.    

    To keep costs down, hull materials are restricted to either wood or glassfiber, while

    masts and booms are restricted to either aluminium or wood.
 

- International Marblehead (M)
    Maximum length: 1290 mm
    Maximum draught: ca 700 mm
    Up to six rigs are allowed, the tallest being about 2200 mm.
 

- International Ten Rater (10R)
 

- International A Class (A), the largest of the international radio sailing classes.
 

The Bottle Boat is a low cost alternative to these classes. Largely constructed from waste items (bin bags for sails and soft drinks bottles for the body), it represents an environmentally friendly entry to the sport.