Mariner-class helmet

Mariner is a UNSC helmet, compatible with MJOLNIR Mark V.

Overview
Similar to EVA, the Mariner base helmet features a bowl-shaped visor, which surrounds the user's face, meeting with metal armor plates along the jaw and back of the head. Either side of the helmet, there is an additional layer of armor that follows the wearer's jawbone up to their ear and the side of their head, and appears to connect up at the back of the head. Just behind the user's ears on either side, there is what appears to be a circular hardpoint for securing attachments like optics to the helmet.

The helmet can be equipped with an additional layer of metal plating, which covers the top of the visor, directly above the user's head. This piece of armor bisected by an extra piece of plating that curves over the top of the wearer's head and stops just shy of the user's eyeline. It can also be equipped with some form of optics, in the form of an eyepiece which is secured to the front of the visor using the two aforementioned hardpoints either side of the helmet. The attachment itself is a rounded, goggle-like apparatus that sits where the visor would be on a traditional helmet. In front of the left eye, the eyepiece module features a large lens jutting out from its front. Meanwhile, in front of the right eye, it features two smaller circular protrusions above and below the user's eyeline. These two attachments can both be equipped at once.

In-game information
The Mariner helmet will be unlockable in Season 5: Anvil of Halo: The Master Chief Collection.

Production notes
During the production of the Defiant Map Pack, two additional armour sets were also produced, codenamed  and. These were intended to be released alongside the Anniversary Map Pack later that year, but were cut due to time and resource constraints, as confirmed by 343 Industries employee David Ellis. "Condemned" consisted of the Mariner helmet and the chest piece now known as EXO/TSCS, meanwhile "Preserve" consisted of the helmet now called AKIS with an unidentified chest piece. Ultimately, none of the new armor was released for Halo: Reach on Xbox 360, though the AKIS helmet and EXO/TSCS chest piece were both seen in promotional material for the Defiant Map Pack, leading to much fan speculation.

The existence of the helmet that would become Mariner was not discovered until modder Gamecheat13 uncovered customisation renders of these two cut armor sets in the game files of the second Halo Insider flight (dubbed the "FireFlight") of Halo: The Master Chief Collection's PC port of Halo: Reach, in 2019. The helmet was not featured in the port at launch, however.

Eventually, in September 2020, 343 Industries confirmed that the helmet had been finalised and polished for inclusion in the game, would be available as part of Season 4: Reclaimer of MCC, alongside all of the other armor pieces from the two sets: AKIS, EXO/TSCS and "Preserve". However, it was later delayed, due to difficulties encountered during development.

The helmet's name, "Mariner", was officially revealed on the MCC Development Update on November 2020, along with the confirmation of both AKIS and Mariner helmet being present in Season 5.

Trivia

 * The helmet's namesake, "Mariner" is defined as a person who navigates or assists in sailing a ship. In addition, Mariner is also the namesake of the Mariner Valleys on Mars, named after the Mariner 9 orbiter.
 * The renders (found below) show a different base model was planned or modeled previously, similar in appearance to the Mark V EVA-class Mjolnir also seen in Halo: Reach. This earlier model seemed to have an extended visor up to the top of the head, and a potential up-armored plate attachment would have been available, with and without the OPTREX module attachment. It is likely designers felt this model would have been too similar to EVA, hence affixing the plate as an integral feature of the helmet design.

List of appearances

 * Halo: Reach