The Farr 40 One Design is the latest collaboration of Farr International, Inc., and Carroll Marine, Ltd. As designers and builders, these two sailing brain trusts are clearly among the best in the world. As the creators of successful big-boat one-design classes, they may well be the best. More and more racing sailors are challenged by the prospect of competing on a level playing field; the new Farr 40, designed to fill the niche for a midsize boat between the Mumm 30 and the Corel 45, demonstrates the rising popularity of one-design racing-31 boats were sold the first year.