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When racing or building, one must adhere to the Class Rules for the particular class of boat.  For the FORMULA 48 Class, rules have been specifically kept to a minimum to encourage new ideas, designs and concepts.  This class is a "DEVELOPMENT CLASS" of boat, where everything is legal unless noted otherwise.  Basically, the boat must have two or more hulls, but can be of catamaran, trimaran, or proa design.  Overall length and overall beam is specified, as is maximum sail area.  Please see the Class Rules (below) for specific rules, measurements or requirements.

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bulletTHE HULLS:
bulletTHE RIG:
bulletTHE SAIL(s):


The Formula 48 Class is an open and fully developmental class of Radio Controlled sailing multihulls, administered by owner/members of multihull yachts meeting the class rules. As a Class Owners Association, it is the owner/members who will decide on rules, vote on any required changes, propose any new rules, and control class specifications.


  1. Boats eligible to participate in this class will have a minimum of two (2) or more hulls.
  2. The overall length of the boat will not exceed 1220 mm in length. (48 inches-reference)
  3. Transom mounted rudders will be included in the overall length.
  4. The overall beam of the boat will not exceed 1220 mm in width. (48 inches-reference)
  5. Hulls may be of any design and constructed out of any material, but must
    not exceed measurement limitations
  6. There is no minimum weight for the boat, the rig, the sails or all-up sailing weight.
  7. Hull identification marks are optional - but not mandatory.
  8. Moving ballast is permitted, but cannot be heavier than lead. Water ballast is permitted and can be added, moved or removed during racing.
  9. The front of all hulls, amas, or floats must contain some form of elastomeric (bumper) material.


  1. The rig ( that part which supports the sail or its equivalent) may be made of any material, construction or design, providing it meets measurement limitations.
  2. When any portion of a mast(s) supporting a soft sail, exceeds 19.045 mm in the fore/aft measurement or 19.045 mm in diameter in the case of a round mast the vertical surface area must be included as part of the calculated sail area. (3/4 inch reference)
  3. When any portion of a boom (jib or main) exceeds 19.045 mm in vertical dimension, or 19.045 mm in diameter if round, the vertical surface area of the boom(s) must be included in the total calculated sail area. (3/4 inch reference)
  4. Rigs with sails that can be reefed, are allowed at major regattas or class championships. The sails attached to the rigs may be of any legal size, shape or design. The "RIG" may not be changed during a race, but it may be changed between races to compensate for changes in wind strength. Sails, if reefable, may be changed during a race to compensate for changes in wind strength
  5. Multiple masts on a single boat are permitted. When using one or more masts on a single boat, the total number of masts count as one rig for purposes of Rule C-4 (above).

 D. SAIL (s)

  1. The sail area will be limited to a calculated area of 0.9 m2 (1394.00 square inches reference).
    See Rules #C-2 and C-3 above.
  2. Kite sails are prohibited
  3. Spinnakers may be used only during one-way speed trials. There is no limit to spinnaker size, shape or area.
  4. Sails may be of any design (except for Rule D-2 above) and constructed out of any material, but must not exceed measurement limitations
  5. If a solid wing sail(s) is used, the total calculated sail area shall include all vertical surface area exposed to the wind. The thickness of any solid wing or wing mast shall not be part of the calculated sail area.
  6. At a minimum, at least one (1) sail shall carry the class logo, the assigned sail number and the abbreviated name of the home country. Sail graphics shall be such so as not interfere with the legibility of the logo, number or country. If area permits, sail numbers are encouraged on any headsail as well as the main sail.


  1. The U.S. Formula 48 Class Owners Association (herein after called the Formula 48 Class Association) is the current authority for this class and administers all rules.
  2. Rules for the class may only be changed every ten (10) years and requires an 75% majority of votes cast by registered owners. The Class Association retains the ability to make minor and insignificant changes to rules during this ten year period, providing changes are for clarification purposes only, and do not impact the intent of the rules. Such clarification changes made do not require the vote of the membership, but must be announced prior to making the change.
  3. The Formula 48 Class Association shall have the authority to set membership requirements for the class, including, but not limited to any membership fees. Membership fee changes are not subject to the ten year rule change limitation. Members from outside the United States may join as members, but may not vote unless they are also a currently registered AMYA member.
  4. There is no building fee required to be paid to the association.
  5. Advertising, is open, unrestricted and permitted. Sponsorship of any yacht is permitted.
  6. Skippers and/or owners are responsible to assure their boats meet the measurement rules, and boats are subject to random measurement checks at regattas.
  7. All measurements given are maximum, meaning dimensions exceeding the amounts shown are prohibited. Dimensions, lengths and sail areas must be exactly the dimension shown - or smaller.
  8. Sail areas shall be calculated using any normally accepted method for mathematically calculating surface area.
  9. The Class Association will assign sail numbers and provide the class logo to any registered member. Sail numbers shall be of a size and thickness to be easily distinguishable by race committee judges and officials. Numbers shall be of contrasting color to sail material color. Skippers are responsible to assure sail numbers are legible at regattas.
  10. Racing Rules as prescribed by the ISAF-RSD shall be followed for all major regattas or championships, but may be amended in writing by the race committee as provided in the Notice of Race, or posted prior to the start of the race.
  11. Any yacht, currently meeting the measurement and rules requirements for the MINI 40 Class is eligible for the Formula 48 Class.
  12. These rules are Copyright February 2000 by the Formula 48 Class Owners Association. Permission to use these rules for unlimited reproduction for the purpose of education of potential new members is hereby granted.

 These rules are supplemented by the following documents unless herein amended:
ISAF Radio Sailing Division "International Class Administrative Rules"
ISAF Radio Sailing Division "Sail Identification Mark Rules"
ISAF Radio Sailing Division "Resolution, Error and Accuracy of Measurement"

Suggested Methods For Measurements

Mast areas for any plan form are measured only when any average chord dimension exceeds 19.045 mm in the fore and aft direction, with the mast centered (if mast rotates) and Boom areas for any plan form are measured only when any average chord dimension exceeds 19.045 mm in the vertical direction. Area is calculated per the following:

Other Area Calculations

1. The mast area when required for inclusion in the total sail area, is computed by the following formula:

Sm = H x E

Where H is the total length of the mast, from deck to top of mast, E is the average horizontal dimension of the mast (chord length), measured fore and aft and a minimum of five (5) measurements shall be made along the mast length to determine the average chord length.

2. The boom area shall be measured in the same manner when required, and shall be added to the totals of the mast and sail area to determine total sail area.

Sb = H x E

Where H is the total length of the boom(s) measured fore and aft, E is the average vertical height dimension of the boom and a minimum of five (5) measurements shall be made along the boom length to determine the average chord length.

3. Solid wing sails shall have their entire projected vertical surface area measured and must comply with total sail area as specified in these class rules. The vertical surface area created by the width of the leading edge of the wing is NOT included in total sail area. Any leading or trailing edge solid wing "flaps" must be measured separately and included in the total sail area.