Two years ago, residents Rob Goldberg and Burl Sheldon hatched a plan for a trade – a boat for a guitar. Sheldon, who has built boats, was a “great musician without a great guitar,” according to Goldberg. Goldberg, who has a guitar shop, was tired of borrowing boats for family subsistence outings.

They each purchased their own materials and traded time for the projects. Sheldon helped Goldberg select a seaworthy rowing boat, and the pair…