The M or Marblehead Class, sometimes called the "50/800", is a high-performance development class designed by Roy L. Clough of Marblehead, MA in the 1930's as the largest model that would conveniently fit in a standard American car of the time.

It has grown into an International Class, with competitive fleets worldwide.

M's are considered the largest "high tech" R/C model class with active designers/builders and steadily growing numbers of participants. Think of them as the "Formula One" of radio- controlled race boats.

It is a development class (unless specifically prohibited, "anything goes") with the main restrictions being a hull length of 50 inches and a sail area of 800 square inches. The class has matured over the years to produce a high-performance model that can be sailed in a wide range of conditions by changing rigs.

The hull and rigs tend to use advanced materials and techniques. Boats are available from several suppliers who can provide them from basic kit form to fully assembled. There is also an active used boat market at the local level. Many older designs can be made locally competitive with simple updates. The M Class has a large ownership base, with over 3000 registered hulls in the US with that many or more worldwide. It is sailed in most areas of the country. Competition is available from local club to international level.

To get started, first register your boat with the Class Secretary.

Once you have registered your boat, a "measurement certificate" will be required if you want to compete in organized regattas. To obtain this certificate, an official Class Measurer will perform a detailed examination and measurement of the hull, appendages, sails, and rigs and if all are found to comply with class rules, a certificate will be issued.

Registering an M Class

1. Become an AMYA member and obtain your AMYA membership number. No registration number will be issued without an AMYA membership number.

2. Complete the AMYA Yacht Registration form contained in Model Yachting. Include your e- mail address on the form. Make out a check for $10 to Bruce Andersen and mail it with the Yacht Registration form to him. Do not make out the check to AMYA - registration funds are used for Marblehead Class expenses and are not part of the AMYA.

3. If you are transferring ownership include the existing registration number and previous owner's name.

4. You will be issued a new sail number if this is a new registration, or a card with the old sail number in your name if this is a transfer of ownership of a previously registered boat. A new number may be issued if the provenance of the hull is unknown.