ROCKLAND, Maine ― A plan to bring Tall Ships America — a fleet of sailboats that navigate the world to promote maritime heritage — to Rockland this summer as part of the city’s bicentennial celebration has fallen through. “We had great conversations with Tall Ships America but ultimately we decided [the plan] didn’t work from a financial perspective,” Dan Bookham, a member of a group working to bring the ships to Rockland, said in an email Wednesday. The plan to include one of the organization’s ships in the city’s maritime celebration in honor of Maine’s 200th birthday was floated in December.