Seaman can be a generic term for sailor.

Fireman
variation

Airman
variation

Seaman
insignia
Seaman used in a naval military context is the third lowest enlisted rank in the U.S. Navy and other navies. For the U.S.Navy the rank is just above Seaman Apprentice and below Petty Officer Third Class; this rank was formerly known as Seaman First Class. If applicable, the occupational titles of Airman or Fireman (and, formerly, Constructionman) are used in place of Seaman, but the rank remains the same. Advancement to Seaman is attained automatically after a certain number of months in service, barring any disciplinary action.
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