Navy vs Marines
There are several branches that make up the United States armed forces. They are the Army, Navy, Marine Corps (marines), the Coast Guard and the Air Force. The Marines and the Navy were officially established in 1775 by the continental congress, that had specific missions for them both, and, although they would often hate to admit it, the Marines are essentially a special branch of the Navy. The Coastal Guard’s principle duty is to man all sea ports used for entry to and exit from the US. Basically, they are supposed to be on top of everything entering and leaving the United States via the seas.
The Navy’s primary role is to ensure that the seas are free, and that the United States is able to make use of the seas, when and where it is required, by national interests. To add to that, the Navy will also supplement the Air Force power, when the need arises during conflicting times. Also, Navy ships can be used to launch an attack on a land target from miles away, using very heavy guns and cruise missiles. Stealth attacks on enemy targets can also be carried out using the Navy submarines. Another primary function of the Navy is to transport Marines to the place of conflict. The Naval reserves will provide assistance to the Navy when it is required.
The Marines are a branch of the United States armed forces that specialize in amphibious missions. They are trained to capture and take control of ‘beach heads’, and to make an attack route that will enable assault on the enemy from almost any direction. The Marines were first established as a landing force for the Navy. The Marine Corps were then made a separate service, by Congress, in 1798. Although amphibious missions are their primary specialty, recently they can also take part in ground combat operations. Since they are basically a ‘lighter’ force than the army, they can be rapidly deployed. During combat missions, the Marines are usually, to a large extent, self-sufficient, with their own airpower that mainly comprises of fighter aircraft and attack helicopters. Even though this is the case, the Marines will, to a large extent, be assisted by the Navy, logistically and administratively. For instance, many of the medics that are with the Marines during combat, are actually trained medics from the Navy.
Summary
The Navy specializes in controlling the entry and exit points of the sea ports, while the Marines carry out amphibious combat missions.
During times of need, the Navy will supplement the Air Force power, while the Marines support the Army when rapid deployment is needed.
Unlike the Navy, the Marines are not completely independent, as they will occasionally rely on the navy for logistical and administrative support.