GRSC Navy (Earth-2042)

The GRSC Navy (GRSCN) was the branch of the GRSC Armed Forces responsible mostly for naval warfare and operations in space, though they still operated in the oceans with their terrestrial arm. Its roles included ship-to-ship combat; orbital bombardment; the deployment of atmospheric and starfighters, and the delivery of GRSC Marines into combat.

It was succeeded in the Galactic Empire by the Imperial Navy.

Source

 * https://www.halopedia.org/UNSC_Navy