Unfortunately, the 1.34 "constant" is true for monohulls with a fineness ratio of about 3:1 or 4:1 (J/24 is ~2.8:1, based on ~22' waterline length:8'6" beam) but not for typically much finer multihulls. The beam of each hull on your Prindle is less than 2', which combined with a waterline length of 16', leads to a "constant" more like 3 or 4. Thus theoretical top speed under sail is more like the high teens. I know the speed record, under controlled conditions, for the Hobie 16 is 26.7 mph (or is it knots? I'm not sure) but anyway much much faster than the 1.34 constant would suggest. Naturally, more fineness leads to a higher constant.

sail fast