The Ten Rater Class

Featured in Model Yachting #133

Click for larger photo!
Mark Gee and his 10R

Class Secretary

Class Secretary
John Kelsey
9010 Moccasin Lake
San Antonio, TX 78245
210 367-1652
Class Administrator
Kenneth Weeks
8807 Ridge Gate St.
San Antonio, TX 78250
210 326-3321


The 10 Rater is a medium to large size developmental class yacht with a reputation for speed. Also recognized by AMYA as an International class, worldwide support for this graceful yacht promotes racing and design advancements on the very leading edge of performance. The name "10 Rater" refers to the formula used to determine the legality of boats within this class. If, after working through a formula, you arrive at a number of "10" or less, then you have a boat that fits into the 10 Rater class.

The 10 Rater class of model yachts is based on the length by sail area rule of 1887. Shortly after this rule was adopted for rating full sized yachts, model builders began using the rule as a foundation for new boat design. The 10 Rater class is unique in its method of "rating" yachts, where the only two parameters that matter are waterline length and total sail area. However, as each parameter contributes toward boat speed, their relationship may only change inversely: as one goes up, the other must go down. This allows 10 Raters to be highly specialized for local performance, or in the most extreme sailing conditions worldwide. The present 10 Rater class-rating rule allows builders the greatest freedom to experiment with performance improving design and technology.

With such latitude allowed in boat design, the tradition of constantly evolving design innovations and construction materials continues today. The "rigs" on 10 Raters are not limited only to soft sails, but may use rigid wings, or a combination of soft sails on wing masts. Each of these performance enhancements is not overlooked, and is counted toward the total sail area; while no design or material restrictions are imposed, no free areas are given either. The result of this unique rating method is an unparalleled efficiency with which 10 Raters extract power from the wind. Below these powerful rigs, 10 Rater hulls are open to experimentation as well. Hull construction materials and techniques are often hi-tech and state of the art, although modern wood construction may still be used to produce competitive yachts. The greater emphasis is on design innovation, with a steady stream of new ideas coming from the drawing boards of both amateur and professional designers. Builders have many choices of plans and modern kits available to suit their local waters. Prices are reasonable, given the high performance and durability of these products. The added value of over 100 years of progressive development that is built into every 10 Rater, is not available in any other class.

Being one of the fastest and most technically demanding of all monohull model yacht classes, the 10 Rater is not a beginner's boat. It is more the "Major League" of the sport of model yacht racing. This gives the Class a relatively small population in local areas, but a worldwide popularity among veteran skippers who enjoy the challenge of competing at the highest level. With the recent introduction of several entry-level model yacht classes, more skippers are discovering the sport than ever before. As many of these new sailors are already looking for greater challenges, there has come a renewed interest in the advanced classes, like the 10 Rater. This has created some new fleets and promoted the growth of existing fleets, which insures the 10 Rater class a bright future to match its long and illustrious past.

10 Rater AMYA Class Rules

Effective 2002

The AMYA 10 Rater Class adopts the International 10 Rater class rules, as they may be amended.

For the most current version of the International class rules, interested parties should check the ISAF-RSD web site. Look under printable documents and scroll down to the 10 Rater class section to find class rules, measurement forms, and other class documents.


As an International class, 10 Rater registration is a two-part process: AMYA registration and International certification. If you are already an AMYA member, send boat information to the 10 Rater class secretary. Be sure to include the $7 fee, and you will be issued an individual registration number. As stated in the International Class Administrative Rules, the last 2 digits of your registration number will be your sail number. Special requests for sail numbers will try to be accommodated. For International 10 Rater class registration, boats will need to be measured and certified by designated officials within AMYA. Contact the 10 Rater class secretary for more information on International certification.