The United Nations Navy is the branch of the United Nations Military responsible for protecting humanity's interests on the final frontier.
With both their massive fleets and Marine detachments, humanity has created a massive foothold alongside both the Nironian Collective and Systems Coalition that has greatly attracted the attention of the Assembly.
Ever since Humanity arrived on the galactic landscape, their navy has always been a sight to behold. While only possessing roughly 150 vessels at the time of their arrival, that soon changed as humanity and its colonies began dumping trillions of dollars and heaps of resources into creating a fleet that marveled even that of the Systems Coalition. Come 2180 CE, the United Nations Navy possesses thousands of ships belonging to five incredibly powerful fleets, dozens of smaller fleets, and hundreds of flotillas across the galaxy. With that massive force, the Navy have been tasked with protecting humanity across space, whether that be guarding space stations, planets, colonies, or otherwise.
On top of those responsibilities, the Navy work hand in hand with the Trailblazer Program, providing support to their colonization/exploratory efforts and Marine training to Trailblazers.
The Admiralty Board is a collection of the Navy's fleet admirals and led by the United Nations Prime Minister tasked with overseeing the United Nations Special Missions Division and determining the outcome of important decisions. While the Admiralty Board hardly ever meets in person, they convene via augmented reality once a week to determine the state of the navy. On special occasions, the Board will meet at Cerberus Station to hold trials or other important events.
While it's official home remains Washington Outpost, the 5th Fleet is the only nomadic fleet the United Nations possesses. The fleet patrols the galaxy, serving as a morale boost to Human colonies and a reminder to all others of what is to come if any conflict arises. No fleet, criminal or otherwise, has ever survived an encounter with the 5th Fleet.
Similarly to the Marine Corps back on Earth, the United Nations Marine Divisions serve as the Navy's weapon on land. With a massive surge in enlistment rate following humanity's first contact with the rest of the galaxy, the UN have been able to field a whopping ten active duty regiments with even more reserve regiments resting at various posts throughout the galaxy.
Regiments 1-4: Cerberus Station
Regiments 5-6: FDR Station
Regiments 7-10: Washington Outpost
Contrary to the Marine Divisions, the Frontier Regiments serve as peace keeping forces throughout the human frontier. Their primary purpose is to ensure peace across the UN's numerous colonies, as well as providing support to the Trailblazer Program in an attempt to expand the frontier.
While they may be primarily stationed in one sector, each regiment spans several sectors and has at least some influence in a vast majority of the Human frontier.
Regiment 1: Alpha Centauri Sector
Regiment 2: Silradar Sector
Regiment 3: Flavian Sector
Regiment 4: Tolkien Sector
With much of the Admiralty Board coming from the United States, the ranks across the UN Navy mirror those of the United States Military perfectly.