Spars, sails and rig are the power unit of a sailing boat. Exposed permanently to the elements, yet readily accessible, they are the part of any vessel, which deserves major attention to good installation and efficient running. In the most perceptive work ever written on the subject, Matthew Sheahan concentrates on every aspect of yacht spars: masts, booms, spinnaker and other poles, together with the wire rigging which is integral with them. After looking closely at rig types and their properties and detail, a major portion of the book is devoted to systematic setting up and tuning for each common rig configuration. Further chapters deal with such matters as reefing, unusual spars, ancillary equipment and important routine maintenance. Masts, booms, spinnaker poles, reaching struts and jib booms, as they are affected by: Materials old and new, construction, surface finish, wire and rod rigging, breaking loads, cruising, passage making, racing, numbers of spreaders, hydraulics and special design requirements.