Winter-class prowler

The Winter-class prowler, also known as the Winter-class stealth corvette, is a UNSC stealth corvette which is a type of Prowler in service with the UNSC Navy, primarily designed for speed and stealth with the purpose of deep-space reconnaissance. Winter-class prowlers commonly monitor former member species of the Covenant and human insurrectionists, precautionary measures taken by the Office of Naval Intelligence to ensure humanity's safety. Ships of the class are typically designated with the hull classification symbol PRO, though those that receive the prototypical upgrades have the IX hull code, denoting an "Unclassified Miscellaneous Unit".

Hull and superstructure
Somewhat similar in functionality and design to the s used by the Office of Naval Intelligence in the early 26th century, prowlers of the Winter class are constructed with a smaller and more compact frame than other prowler classes. With an aerodynamic frame, swooped back wings, and narrow cockpit, Winter-class prowlers bear resemblance to a number of UNSC space fighters rather than a warship. However, its design is intended to improve speed and versatility during atmospheric operations.

Propulsion
The Winter-class is equipped with an experimental set of three fusion drives, which are only distantly related to their mainline UNSC counterparts. These utilize new Baffler technologies and control software, and are so advanced only ONI technicians are qualified to maintain them.

Some examples of the class, such as the ONI Acrisius, are fitted with a prototypical slipspace drive. This allows these select few craft to travel to distant parts of the Milky Way at a relatively high speed, monitoring the ex-Covenant races and human Insurrectionists for signs of trouble.

Crew and complement
Five personnel are enough to optimally crew each Winter-class, with each being reserved a station in the prowler's bridge; a Commander, a navigator, a technician, a tactical director and surveillance controller. However, only the first two are required to operate one of these vessels, with the latter three spots only being filled during infiltration missions. Nevertheless, each individual is highly skilled, with the Commander receiving specialized training on concealment and deception. This is because each person has been sourced from the so-called "Prowler Corps", whose traditions and secrets separate them from the rest of ONI, and indeed, the rest of the UNSC.

A maximum of twenty passengers can be carried by the prowler. These can include remote strike teams, which are deployed with high-yield nuclear warheads close to heavily-fortified invasion beachheads and staging areas - an operation which many rarely survive. For other missions, covert field teams could be carried which can be ordered to redirect enemy attention away from the prowler, should they get close to discovering the vessel.

Armament
Like every other model of prowler, the Winter-class is only equipped with a modest arsenal of weapons. The most powerful of its armaments is its aft-mounted CBU-R68 Moray mine rack, which deploys potent explosives with small chemical propellants that allow them to maintain specific coordinates in space. This allows the Winter-class to act as a minelayer, covertly creating minefields to inflict casualties on unsuspecting Covenant fleets. Two M8545 40mm coilguns are fitted for purely defensive purposes.

Sensors and countermeasures
While not truly invisible to Covenant sensors, the Winter-class is outfitted with an impressive suite of cloaking technologies designed to distort their emissions and sensor profile. This allows these ships to trick Covenant sensors into identifying the Winter-class as a low-threat vessel, wreckage, or even a friendly ship. While it utilizes the best jamming systems available to ONI, most of its success can be attributed to its low observable design and passive stealth features. This includes metamaterials embedded in the prowler's hull plating to break up its thermal emissions, programmable optical camouflage coating and heat sinks to prevent the release of said emissions. During the post-war era, these systems were further enhanced with the integration of active camouflage systems and emission distortion grids. This addition allows these modified ships to evade all but the most comprehensive detection techniques and sensor networks. Remote drone networks can also be deployed to divert attention away from the ship itself. All this is supplemented by a cutting-edge Hyperscanner sensor array, along with threat warning and tracking systems systems derived from analysis and repurposing of Covenant technology.

Should it somehow be detected, the Winter-class has one last defense in the form of three pop-up turrets, one directly behind the cockpit and two on the wings. Each of these contain two anti-missile pulse lasers and an electronic warfare countermeasures dispenser. This dispenser can release a variety of consumables from heat sinks to deception jammers to mislead enemy sensors and break target locks.

Operational history
In the years following the Human-Covenant War, the Office of Naval Intelligence reviewed a number of pre–2525 prowler class designs which focused on espionage and reconnaissance over combat functionality. As a result, the Winter-class prowlers arose from this study, coming into service with Naval Intelligence in 2549. On January 21, 2558, Winter-class prowler deployed SPARTAN-G059 to New Llanelli to assassinate Avu Med 'Telcam, leader of the Servants of the Abiding Truth. Afterwards, the prowler extracted the Spartan and left to participate in another operation. The Spartan-IIs of Gray Team now operate out of the Winter-class prowler.

Another Prowler, the was dispatched by Intrepid Eye to take Papa-10 and Lieutenant Bartalan Craddog to Meridian to retrieve the organs of the Tuwa family during Operation: RETRIBUTION. However, the mission failed and both Papa-10 and Craddog were killed.

One Winter-class prowler—the ONI Acrisius—was stationed aboard research vessel Argent Moon as an evacuation vessel for its ONI personnel. However, the crew of Argent Moon were all killed in a bioweapon accident in 2557. When Spartan-II Blue Team traveled to Argent Moon to prevent ONI intelligence from falling into the hands of Jul 'Mdama's Covenant, the Spartans used Acrisius to evacuate Argent Moon after they overloaded its reactors as their Pelican had been destroyed. The ship was eventually abandoned by the Spartans on the Outer Colony of Meridian, when they traveled to the world to search for Cortana and instead left on a Guardian.

Ships of the line

 * ONI Acrisius (IX-455) – Stationed at Argent Moon as an evacuation vessel.
 * - Stationed at Argent Moon.
 * – Deployed on covert Office of Naval Intelligence operations.
 * – The operating base of Gray Team.
 * – The lead ship of the class.

List of appearances

 * Halo 5: Guardians
 * Limited Edition dossiers
 * Halo: Tales from Slipspace
 * Knight Takes Bishop
 * Halo: Retribution
 * Halo: Warfleet