The 21 footer restrictions


The following measurement rules were published in 1934 by the Yacht Racing Association, and were noted as being in force since 1928.

Length over all Not to exceed 25ft
Length on the LWL In racing trim, but without crew, not to exceed 21ft
Beam From outside of planking, measured at the greatest breadth, shall not be less than 7ft. Not more than 8ft.
Draught of water In racing trim, as above measured at .55 of the length of LWL from its fore-end and at the heel, not to be less than 1ft 8in (being the difference between the skin girth and the chain girth) measured at .55 of the length of the LWL from its fore-end, from the top side of the covering board, or the underside of the outwale or batten on one side, under the keel to the top side of the covering board or under side of the outwale, or batten on the other side, as the case may be, in a plane at right angles to the waterline, not to be greater than 7in
Freeboard Measured in racing trim as above, not to be less than (a) at the lowest point 1ft 6in not to be less than (b) at stem (top of covering board or intersection of line continuing the fair sweep of the centreline of the top of the deck and face of stem) 2ft. There are to be no bow transoms.
Stern ‘Square’ fromed by a flat transom fitted to the after moulding of the stern post in fair straight line with the full length of the stern post, with a rake aft from the LWL to the centreline of the top of the deck, measured along the plane at the LWL, not less than 1ft
Stern post To be in fair straight line with the back of the transom to a point measured vertically below the LWL, not less than 1ft 8in
Cockpit Area of opening (including movable hatches) in superficial feet, not to exceed 42
Sail area Measured as prescribed by YRA rules for the year 1921. Not to exceed in superficial feet 450. NOTE: Under YRA rules the fore-triangle is taken at 85 per cent of its true value.
Ballast Is to be all inside, minimum weight 10cwt (except in the case of yachts built or under construction prior to January 1st, 1925). That measurers weigh and mark weight on each piece of ballast, and mark the position of ballast in boat. An anchor of not less than 25lbs shall be carried on board when racing.
Mast, spars, sails All solid, except gaff or yard. These may be hollow wood. In races for the Forster Cup only one mast, or duplicate thereof, shall be used. That boats be limited to two mainsails and two sets of spars.