The Practical Mariner's Book of Knowledge is either the most useful boating book ever designed to entertain or the most entertaining book ever designed to be useful. In its alphabetical organization that juxtaposes wildly disparate entries, you can read about the derivation of fi gureheads where you turned to for recommended thicknesses of fiberglass hulls. In between the whimsy, however, is the essence of centuries of seafaring experience distilled into a concise reference for sailors and powerboaters. There may be no substitute for a lifetime of...