In cold analysis, cruising is a ridiculous way to get anywhere,"" says William Robinson midway in his World of Yachting. But men have gone down to the sea in ships for pleasure at least since Charles If of England found delight in Dutch jachting. Mr. Robinson holds a steady course on the life of yachting in England and America from that time, and it must be heady to know that ""the yachtsman who is partial to the sea skiff today can trace the ancestry of his boat in a fairly straight line through the Sea Bright dories back to the Viking ships."" He takes up the fortunes of Chris-Craft, small boat voyaging (initiated by Captain Joshua Slocum who sailed alone around the world and wrote about it), distance racing, one-design racing, the great yacht designers, the unique America's cup, luxury yachts then and now, and the outboard revolution which is a far remove from the white flanneled set of the early 1900s. Appendices indicate winners of famous races, Olympic winners since 1928.