§3861. Framing of issues
At the request of either party, the following questions of fact shall be submitted to a jury: "What amount claimed in the complaint is due from the defendant to the plaintiff?" and "For how much of such amount has the plaintiff a lien on the vessel attached?" The verdict shall be in answer to these questions. If the parties waive a jury trial, these questions shall be decided by the court on a hearing or report of a referee appointed by the court.