Individuals armed with specialized knowledge make up the Specialist ranks. Neither ranking with the enlisted personnel nor commissioned officers, they are the "middle stepchildren" in the naval service.
Specialists come from either two sources: senior non-commissioned officers, or civilians with specific training. Granted a warrant by the naval board of the respective power, they are considered by courtesy to be an officer (through not commissioned). Warrants must be issued for each ship the Specialist is assigned too, and the warrants can be revoked at any time. Traditionally, they are defined as ranking above the enlisted ranks, but below the commissioned officers.
Specialists may only command personnel directly placed under their command, however. Specialists are predominately engineering or weapon tech. On smaller ships, they may even be in watch supervisory roles. One specialist position eclipses all other specialists, and this is the Master. Master(s) are uniquely appointed Specialists in the Rosebourg Navy.
Masters are charged with the safe navigation of the smaller frigates and support craft. They are considered department heads for navigation on the craft mentioned above. They outrank many junior officers with their warrant stating that they: "rank with but after lieutenants" Considered a de-facto commissioned officer, they occupy a senior officer's quarters and receive officer level pay.
Prospective Masters are put through a rigorous training program, which fails about 85% of applicants each training cycle. Frequently, a Master is given a commission and a position such as senior navigator on the larger cruisers after a few years service time. Yet for POW purposes, Masters are considered to be specialist officers. Specialist officers cannot give their word as "a bond" (commissioned officers can), and almost always are grouped with the enlisted personnel in POW situations. With these contradictions, Specialist officers continue to be a driving force in a major power's naval service. Doing their specialized jobs, these people keep the ships running efficiently.
Specialist Officer Rank Table:
S1 - Warrant Specialist Officer S2 - Chief Warrant Specialist Officer S3 - King's Specialist Officer (King warrants the officer -- instead of the naval board) M1 - Master (Highest Ranking Specialist Officer - Ranks informally above a 06 Senior Ensign or O1 Flight Cadet, but below an O2 Lieutenant Junior Grade)