Surgeon's mate

Assistant to the person responsible for the health of a ship's passengers and crew

A surgeon's mate was a rank in the Royal Navy for a medically trained assistant to the ship's surgeon. The rank was renamed assistant surgeon in 1805, and was considered equivalent to the rank of master's mate/mate. In 1807, first-rate would have three, a third-rate two, and frigates and sloops one.

This keyword could refer to multiple things. Here are some suggestions: