Petty officer third class

Petty Officer Third Class is the fourth enlisted rank of the UNSC Navy and is the lowest rank of non-commissioned officer. It is equal in rank to Corporal in the UNSC Marine Corps.

In informal settings, Petty Officers Third Class are typically called "Petty Officer".

Tech Officer Third Class
Tech Officer Third Class is the lowest technician rank in the military. It is a specialist rank.

Tech Officers provide technical support wherever they are needed. They are specially trained in technical issues and help keep UNSC ships running. Almost every ship requires technicians to run. UNSC Technicians usually wear color-coded uniforms to help others differentiate, rather than to read a small badge during hectic combat conditions where every second counts. Tech Officers in the Third Class are the freshmen of all technicians, mostly new to the job.

Technicians are usually armed with M6D pistols in case of boarding actions, and they can use their hard-hitting and effective side-arm to hold off hostiles long enough until friendly support, probably in the form of UNSC Marines, arrive. However, some remain unarmed, preferring to keep their hands free.

Technicians, although usually in combat areas, have probably received little or no combat training. It is not unusual to see technicians cowering in fear during combat situations.

Tech Officer Third Class appearances
Technicians appear in Halo: Combat Evolved and Halo: PC, in the level "Pillar of Autumn" and "Halo". Some are shown holding M6D pistols fending off Covenant boarding parties, while a few are unarmed.