For new boating enthusiasts--even if they've been at it awhile--there are scores of burning questions. If one boat has a round bottom and another's is veed, what difference does it make in the way they perform? What are the advantages of a cutter rig over a sloop? Why does one sailor swear by a full keel, while others won't have anything but a fin keel? Why does one powerboat have more flare in its topsides than another? And what is flare? Why...