What is the us navy rank sr?

SR is the designation of a Seaman Recruit, E-1. This means that they are in boot camp. On completion of boot camp they would be promoted to Seaman Apprentice, or SA.
SR is the designation of a Seaman Recruit, E-1. This means that they are in boot camp. On completion of boot camp they would be promoted to Seaman Apprentice, or SA.