Friendship of Salem is a 116-foot exact replica of a 1797 merchant vessel is in New York this weekend at the North Cove Marina in Lower Manhattan. The vessel is usually home-ported at the Salem Maritime National Historic Site in Massachusetts. The public is invited aboard to tour the ship for free Saturday from 10:30 a.m. to 3 p.m. The three-masted square-rigger is on a goodwill tour that’s also giving 33 National Park Service interns hands-on experience. All shipboard commands are given in late-eighteenth-century language, and volunteers do everything from sanding to painting to climbing the rigging high above the deck.