UNSC Navy

The UNSC Navy (UNSCN) is a human naval force, and one of four military branches of the UNSC. It is responsible for all naval operations in space, including but not limited to: interstellar transportation, ship-to-ship combat, deep-space law enforcement and expeditionary operations. Along with the UNSC Marine Corps and elements of the Air Force, its field units fall under the authority of the unified Naval Command.

The Navy was birthed in response to the widespread violence that predated the Interplanetary Wars, and quickly grew due to the influx of assets and personnel belonging to the defunct United Nations Colonial Peacekeeping Force and various international armed forces. At first, riots and unrest in the Sol system meant that they remained largely confined to the region for the first two centuries of existence. Throughout the twenty-fifth century, they expanded rapidly to become the largest human-dominated naval force in history, thanks to successful attempts at usurping the existing Colonial Navy. They played a major role in both the Inner Colony Wars and the Insurrection, where they enforced sanctions on rebelling colonies, transported counter-insurgency units to trouble-spots, and delegated ships to protecting and searching civilian vessels. The UNSC Navy was authorized to take control of all naval assets and personnel at the beginning of the Human-Covenant War. In spite of this, they took horrendous losses at the hands of the Covenant; even with replacements, their fleet dropped from 2,034 ships to only 489 slipspace-capable warships at the conflict's conclusion.

Field formations
The UNSC Navy's organization for its starships has evolved and changed several times over the course of its lifespan, with the most modern iteration prioritizing easy reassignment of units and autonomy among its local headquarters spread throughout human space. Their naval forces are broadly divided into two main groups of formations, colloquially known as 'temporary' and 'permanent' forces. Temporary forces are custom-built for the needs of a single goal, and are immediately disbanded upon its completion. Permanent units are more general-purpose assignments whose duties are often locked within operational regions. They are only 'deactivated' when either their spacecraft are unavailable for assignment, moved to new commands, or are deemed impossible to practically support them in the foreseeable future. This does not always correspond to when moving ships are placed into temporary formations; squadrons assigned to task forces still retain their individual name and setup.

Regional fleets
Commanded by a Fleet Admiral (O-11), homeported at every system that hosts one of the UNSC's five Central Command Headquarters (ie, the main command base for each quadrant + Sol). All formations that are normally assigned to a quadrant are organised under some subdivision of a Sector Fleet, although in practice they rarely interfere with the operations of their subordinates. The 'main portion' of the fleet is typically made up of one or two Numbered Fleets, with independent squadrons backing them up.

Regional fleets are named after the system they operate from, and follow no standardized template upon their creation. Instead, their expansion tends to be spontaneous based on a perceived need.

FLEETCOM Sectors
FLEETCOM Sector Commands coordinate UNSC fleet operations in much smaller regions of space, with multiple Numbered Fleets working beneath them. This is more of an administrative level that puts the UNSC's grand strategy for their region into practice. They authorize the creation of temporary task forces, resolve conflicting orders from subordinate units, and exchange information with non-Navy liaisons to ensure that the other branches assist or are made aware of upcoming operations. They are typically commanded by an Admiral, who is normally advised by a council of high-ranking officers spread throughout their sector.

Numbered fleets
Commanded by a Vice Admiral (O-9), Numbered Fleets are tasked with an 'area of responsibility,' typically centred around a handful of star systems. During peacetime, this corresponds to ensuring the safety of a handful of human colonies and star systems, while in wartime, they are pulled together into larger theatres and tasked with pursuing broad goals. They are made up of between 3-4 Groups/Armadas as well as a small handful of extra squadrons, and are the smallest naval formation that are truly self-sufficient thanks to a logistics division.

Groups
Commanded by a Rear Admiral (O-8), these are subdivisions of Numbered Fleets that fulfil a basic need necessary for their functioning - for example, logistics, planetary assault, and strike units. They are normally made up of a Squadron or Flotilla escorting a large starship, such as a heavy carrier or assault ship.

Squadrons
Commanded by a Commodore (O-7) unless already within a Group, these are the 'workhorses' of the UNSC Navy, and are designed to be easily reassigned under different commands (e.g. move from fleet-to-fleet, or get retasked to different theatres). They undertake specific objectives delegated to them from higher commands, and are the smallest unit in which Capital Ships (e.g. Cruisers, Carriers, etc) are organised in. They have between 8 - 12 ships.

Flotillas
Commanded by a Captain (O-6), Flotillas are similar to Squadrons except that they are made up exclusively of non-capital ships. They have between 5 to 10 ships.

Task forces
Joint-operation units where multiple branches outside of the Department of the Navy have assigned resources to a specific goal, and operate outside of the UNSC Navy's regular chain-of-command and in the UNSC's general system instead.

Battle groups
Ad-hoc UNSC Navy units created for a specific mission, controlled by the regular command structure in place for the Navy. They can be of any size and shape.