THE PRACTICAL SAILOR, edited by Roger F. Duncan (Scribner's, $16.95). Roger Duncan is a certifiable old salt whom one suspects has only worked in life that he might make enough money on occasion to pay his slip fees. Formerly the editor of the newsletter by the same name as this book, Duncan has gathered together the kind of nuts and bolts information about sailing that usually is only passed along by word of mouth.

A HUNDRED YEARS OF SAIL: Beken of Cowes (Knopf, $45). For four generations, a British family called Beken has plied its esoteric trade of yacht portraiture along England's most colorful boating waterway, the Solent. And here, in more than 100 photographs, is a sampling of the works of the Bekens. There isn't a single photo in this magnificently printed book that isn't alone worth the price, that by itself, clipped carefully from the volume and framed, wouldn't draw stares and comments.

ROMANCE OF THE SEA, by J.H. Parry (National Geographic Society, $19.95). From dugout canoes to the Queen Mary, the staff of the National Geographic and maritime historian J.H. Parry offer a visual and written log of man's attempts to control sea lanes, reap the protein harvest of the oceans and travel these byways in the best of style. This is an intelligent and innovative attempt to disguise an informative and well-written sea book as one of those unthinking cocktail-table picture books fit only for browsing and boredom.The title is also misleading. This is more a history of the economics of the sea than the romance of blue water and white sails. The typically marvelous Geographic way with informative artwork is commonplace here and best represented by the four-page gatefold of a cutaway view of the Queen Mary at sea: you can see the Smiths in their A-deck cabin changing from dinner. The price makes this a remarkable printing bargain. Other publishers, using lower-quality paper, less full-color work and cheaper binding materials might charge twice as much for such a book.

CRUISING UNDER SAIL incorporating Voyaging Under Sail, by Eric Hiscock (Oxford, $29.95). Oxford apparently understands quite well the market for this third edition of the complete Hiscock because they have wrapped it in a water-resistant cover. The 550-plus pages in this edition are simply the condensed encyclopedia of the technicalities of long-distance sailing. It does suffer from the typical problem of recycled and updated texts--if your boat was built in 1949 when Hiscock first wrote it, your rig, sails and equipment will seem right at home on these pages.