retired Navy, Marine Corps, or Coast Guard commissioned officers, warrant officers, and enlisted personnel, E-6 through O-6, who have served a minimum of 20 years of active duty. The Head of the Department of Naval Science at a school hosting an NJROTC program is called the Senior Naval Science Instructor (SNSI). The SNSI is the commissioned officer or Warrant Officer (with degree) employed by the school. Enlisted personnel or warrant officers and LDOs without degrees employed by the school in the NJROTC program are called Naval Science Instructors (NSI). Warrant Officers or LDOs with a baccalaureate degree may also apply to the school for employment as an NSI. Either the SNSI or NSI must have retired from the United States Navy. The minimum education requirement for SNSIs is a baccalaureate degree from an accredited college or university.