At 100 feet on deck, Turner is the largest wooden sailing vessel built in the Bay Area in almost a century. At least as amazing as that fact is that most of the construction was done by a volunteer crew that worked alongside the six paid shipwrights. Since the keel was laid, in October 2003, some 400 volunteers, men and women ages 15 to 81, have donated more than 120,000 hours on all phases of construction. Some work twice a month, some twice a week. Some, mostly retirees, show up five days a week.