High Quality Content by WIKIPEDIA articles! A sailor, mariner, or seaman is a person who navigates water-borne vessels or assists in their operation, maintenance, or service. The term can apply to professional mariners, military personnel, and recreational sailors as well as a plethora of other uses. Etymologically, the name preserves the memory of the time when ships were commonly powered by sails, but it applies to the personnel of all vessels, whatever their mode of locomotion.