A hospital ship is a ship designated for primary function as a floating medical treatment facility or hospital. Most are operated by the military forces (mostly navies) of various countries, as they are intended to be used in or near war zones. In the 19th century, redundant warships were used as moored hospitals for seamen. The Second Geneva Convention prohibits military attacks on hospital ships that meet specified requirements, though belligerent forces have right of inspection and may take patients, but not staff, as prisoners of war.