This June, the public will be invited to watch as the oldest Maine-built wooden schooner returns to the river where she was built over a century ago when she is launched into the Kennebec River following a yearlong restoration at the Maine Maritime Museum in Bath. The Mary E, a two-masted clipper schooner, was built in 1906 on the banks of the Kennebec on the grounds of what is now the museum, and is also believed to be the oldest Bath-built wooden vessel. In the century since its construction, the 73-foot tall ship has spent a peripatetic life away from its native city, serving stints across New England as a fishing boat, a carrier ship, a rum-runner, and in its later life, a river tour boat, according to the museum. Early last year, the museum acquired the vessel from a New York owner and embarked on an extensive restoration.