CHATHAM – Select Board members voted unanimously Tuesday to return a historic Coast Guard boathouse to Chatham for use as a municipal shellfish grow-out facility. The boathouse stood at Stage Harbor for over 70 years until it was placed on a barge and towed from Stage Harbor to storage in Hull nearly 12 years ago to avoid demolition. A boathouse preservation committee sprang up to lead the effort to save the boathouse, which again faced demolition this past January in Hull before developer Jay Cashman offered to move it to his facilities in Quincy. The group has offered to raise the money to pay for the storage, repairs to make the structure weathertight, and the move back to Chatham by barge. The committee is applying for Community Preservation Act money to help in that effort.