Poseidon-class light carrier

The Poseidon-class light carrier is a warship in service with the UNSC Navy following the Human-Covenant War.

Design details
The Poseidon-class carrier is sleek, elongated, and somewhat cylindrical in general shape. Its structure comprises two main sections covered with white plating; in the fore section, the plating mostly covers the vessel's dorsal surface. This plating is absent on most of the underside of the ship and in a spar connecting the two main sections. A series of rectangular blue lights are arranged in the sections lacking the white plating. 719 meters in length, the Poseidon is exceeded in both size and tonnage by the Orion, Epoch, and Punic carrier classes.

What it loses in size and armament, the Poseidon makes up for with its ease of manufacture in the war-ravaged shipyards over Mars and Jupiter. The Poseidon additionally only requires a small crew to operate, allowing it to be pressed into service in 2553 - only months after the end of the war.

Armament
The Poseidon is unusual for a UNSC starship in that it does not have a primary Magnetic Accelerator Cannon weapon system; instead, the carrier's heaviest weaponry consists of two Mark 2551 Onager turrets and two M42 Archer missile pods. The carrier's weapons complement is instead more focused on defensive measures, boasting twenty M870 Rampart point defense guns.

Propulsion
The Poseidon-class is propelled in transit by a single fusion drive located on the back of the ship. On at least one vessel,, superluminal travel is accomplished via installation of an advanced Shaw-Fujikawa Translight Engine (SFTE), utilising technology reverse-engineered from alien Covenant and/or Forerunner technology recovered during the Human-Covenant War. This installation allows the carrier to make long-ranged slipspace transits extremely rapidly - fast enough to allow the removal of the ship's cryogenics bays entirely to be replaced with simple seating. It is unknown whether the Milwaukee's advanced SFTE is representative of the Poseidon-class as a whole, due to the ship's specific repurposing as a passenger ferry.

Ships of the line

 * - The lead ship of the class.
 * - The lead ship of the class.

Transport to Sarcophagus
After the shield world of Sarcophagus was discovered and colonised, the was repurposed to carry personnel, civilians and goods between Onyx and the colonies.

New Phoenix Incident
Several ships of this class were part of Battle Group Dakota alongside a number of s and s. These ships engaged the Forerunner vessel Mantle's Approach during the Didact's attack on Earth on July 25, 2557.

Production notes

 * Several Poseidon-class light carriers appear in the background of the Halo 4 level Midnight; given their nature they are intended to be seen only from a considerable distance. However, exploiting a glitch allows the player to examine these vessels up close, along with a number of s and s. Because these ships are intended to appear only as scenery, they are rendered as brushes rather than level geometry; as such, the player can fly the Broadsword through them without harm. By the same merit the ships' in-game models are not to scale with their canonical incarnations.
 * The Poseidon-class carrier and Vindication-class battleship were to be featured in Halo 4: The Essential Visual Guide but were cut due to space constraints.

List of appearances

 * Halo 4
 * Halo: Legacy of Onyx