This is the Class rule for the American X Class. It was adopted in December 1939 by the Model Yacht Racing Association of America (MYRAA).
M. Y. R. “ x” A. A. CLASS (American 1,000 Square-Inch Sai] Area Class) RATING RULES Adopted Dec. 1939 by the M.Y.R.A.A. SAIL AREA (tota] NOT to exceed one thousand square inches, exclusive of roaches. HULL Hull, unrestricted as to the following: (1) Scantlings (6) Beam (2) Materials (7) Draft (3) Displacement (8) Freeboard (4) Load water line Jength (9) Tumble-home (5) Hull, Length over al] Restrictions: (1) Punts, Prams or forward transoms, prohibited. (2) Garboards: Hollow of garboard shal] NOT be LESS than an arc of a circle with a one inch ra- dius. May be checked by use of a disc two inches in diameter, fitted to garboards at any convenient station, (3) Ballast: Weight of lead ballast shal] be changed during a race or series of races. NOT Prohibited: (1) Sliding or adjustable keels. (2) A kee] havingaweb or fin of lesser thickness than 5/16” at its thickest place on its narrow- est waterline plane. (3) (4) (5) (6) (7) (8) Center-boards. Lee-boards. Bilge-boards. Bowsprits. Overhanging,rudders Outriggers, pontoons or twin hulls. (9) Movable or shifting ballast. (10) Prognatous keels; specifically: no portion of the forward or leading edge of the kee] appendage may project forward of any portion of the leading edge above. 54 M.Y.R.A.A. “X” Class RIG Rig, Unrestricted as (1) to the following: Any type of rig allowed, providing batten limits are not exceeded. (2) Alternate, or smaller rigs vided total] (3) limited. (4) sai] allowed, area Jimit is not exceeded. Height of rig, mast, pro- or forestay is not Masts‘and spars may be of any type, section or material, Rig, restricted as to the following: (1) The greatest diameter of mast and spars is limited to one inch. (2) Headsticks or headboards sha]] not exceed one inch across base. (3) Wire or other stiffening shal] not be put in head or foot of sails. Corners of sails may be re-enforced with the same material of which the sail is made. (4) Battens shal] divide the after leach/es into approximately equal parts. MAINSAIL not to exceed four in number, upper and Jower shal] not exceed four inches each in length. mediate battens not to exceed five inches length. JIB BATTENS not to exceed three in each not to exceed three inches in length. BATTENS battens [Intereach in number, (5) Roach of sails shal] NOT exceed two (2) inches. Rounded foot of loose-footed sails NOT measured. Prohibited: Spinnakers. (1) (2) Reaching or Genoa jibs. Sails unfairly sheeted or set No jib or foresail shal] main boom. Two minsai]s shal] be sheeted onto the not beset at the same time. VALIDITY OF CERTIFICATES (See “ Genera] Rules Governing Rating’and Measurement’’)., Rating certificates and Registration Cards are valid only during the calendar year in which they are issued, 55 M.Y.R.A.A. “X”” Class Any changes affecting the sai] area LIMITS cancels Measurement Certificate and Registration Card. A change of owner, club, or name of yacht cancels Measurement Certificate and Registration Card. The onus rests at al] times with the owner to notify his Club Secretary or Measurer of anything whatsoever that may necessitate re-measuring or reregistration. Fo]]owing any such change or alteration the owner shal] surrender his Measurement Certificate and Registration Card to the Club Measurer for cancellation, and such yacht must be remeasured and re-registered before it is again allowed in competition, X-CLASS SAIL AREA MARKS In the X Class, both mainsail] and jib shal] be marked with the officia] M.Y.R.A.A. stamp by the Club Measurer, in the lower corner of sail nearest the mast. The amount of the measured sai] area to be added in the space provided with waterproof or indelible ink. The official M.Y.R.A.A. stamp shal] be an equilatera] triangle with base and sides measuring 7/8 inches with the letters “M.Y,R.A.A.”’ at base, Such stamp to be of rubber and to be had from the M.Y.R. A.A, Registrar. SAIL AREA MEASUREMENT No fore-triangle measurement is taken, ACTUAL sail area, excluding roaches, (See “Calculation of Sai] Area”. only the is measured. ROACH OF SAILS Roach of sails shal] NOT exceed two (2) inches. Rounded foot of loose-footed sai]s NOT measured. CALCULATION OF SAIL AREA See “Genera] Measurement”, Rules Governing Registration and 56