Surgeons of the navyNo such losses in killed and wounded were experienced afloat as in the great battles ashore, yet the naval medical staff, especially on the Mississippi, the James, and the Potomac, were often called upon to cooperate with the army medical staff in caring for the wounded soldiers. There was a surgeon and sometimes an assistant surgeon on each ship. Hospital boats had medical staffs as large as the hospitals ashore. Beside the Red Rover there was the City of Memphis, which carried 11,024 sick and wounded in thirty-three trips up and down the Mississippi, and the D. A. January, in charge of Assistant Surgeon A. H. Hoff, which transported and cared for 23,738 patients during the last three years of the war. Other boats used as hospital transports were the Empress and the Imperial.