Boats in the International Ten Rater (10R) class are not limited in length by the class rules and usually have overhangs extending beyond their waterline endings. They are generally light, narrow, stable, seaworthy and fast. This IRSA international rule is based on the 1887 "length and sail area rating rule" which allows shorter waterline length boats to have higher sail areas, while longer LWL boats have smaller sails. It is an ‘open’ rule with great freedom to develop design and construction, particularly in rigs and sail plans. Many different hull forms can be found in the 10R class. A modern 10R will usually be made almost entirely of carbon fibre - hull, foils, spars and fittings.

The Ten Rater is a thoroughbred racing boat. They are really fast and powerful, making for exciting sailing. Some people have described them as "racing goannas".

Internationally, the class has undergone a resurgence in the last five years. World Championships have been held in 2016 and 2018 attracting many boats. Large fleets are building in England, France, Germany and Italy. Australia has always been a strong country in the Ten Rater class, with good numbers in Western Australia, New South Wales and Queensland Recently, further interest has built in Victoria, ACT and Tasmania.

There are annual National Championships in Australia, as well as State Championships and Regional events around the country.

Class details:

Open class
Waterline length x Sail area = constant (longer boats have less sail area, shorter boats have more sail area)
Carbon hulls, foils and spars
Hull length 1.3 to 1.8 m
Displacement 5 to 7 kgs
Draught 700 mm
Sail area 0.9 to 1.1 m²