The Navy is the branch of the military forces tasked with sea warfare.
In the United States, the United States Navy (USN) is one of the four branches of the military forces, the others being the US Air Force (USAF), the US Army and the US Marine Corps (USMC). In Canada, the Royal Canadian Navy operates alongside the Royal Canadian Army and the Royal Canadian Air Force.
The modern arsenal of a navy includes many types of vessels, the most important being aircraft carriers which project air power from ships which are literarly floating air bases. Some of these planes are legendary, such as the F-14 and the F-18, known throughout the world and featured in the movie Top Gun. Other important vessels are nuclear submarines that take the nuclear arsenal to the sea and are a constant detterent to the navy's enemies.
The rank structure of the Navy is similar to those of the other branches, although the rank names are different. These are the ranks of the United States Navy (the ranks of other countries may have slight differences in appellation):
Enlisted: Seaman, Petty Officer, Chief Petty Officer, Master Chief Petty Officer, Master Chief Petty Officer of the Navy
Officers: Ensign, Lieutenant Junior Grade, Lieutenant, Lieutenant-Commander, Commander, Captain, Rear Admiral (Lower Half), Rear Admiral (Upper Half), Vice Admiral, Admiral, Fleet Admiral (the rank of Fleet Admiral is only used in wartime. The last Fleet Admiral of the United States was Chester W. Nimitz during the Second World War.
In Canada, the rank Lieutenant Junior Grade is instead named Sub-Lieutenant.
As the Posse Comitatus Act of congress forbids the US Navy from operating on American soil, the Coast Guard takes over domestic operations, such as the protection of seaports or law enforcement operations on high seas.
