A sailor, seaman, mariner, or seafarer is a person who navigates waterborne vessels or assists as a crewmember in their operation and maintenance. The term may be used for British or US Navy sailors, the latter especially when deployed ashore as infantry. The Bluejacket's Manual is the basic handbook for United States Navy personnel. 700,000 of the world's mariners come from the Philippines, being the world's largest origin of seafarers.