navy or maritime force is a fleet of waterborne military vessels associated naval aviation, both sea-based and land-based
WHEN YOU SAY NAVY YOU MEAN IKE NAVY SEALS
Naval operations can be broadly divided between riverine and littoral applications 
dO THEY USE AMPHIBIOUS WEAPONS LIKE TANKS OR HOVER CRAFT, LAND SEA AND AIR
Well they sometimes do,but their strategic task of the navy also may incorporate nuclear deterrence by use of submarine-launched ballistic missiles.
IVE BEEN TO THE MARINE BASE IN JACKSON NORTH CAROLINA
Navy
A navy or maritime force is the branch of a nation's armed forces principally designated for naval and amphibious warfare; namely, lake-borne, riverine, littoral, or ocean-borne combat operations and related functions. It includes anything conducted by surface ships, amphibious ships, submarines, and seaborne aviation, as well as ancillary support, communications, training, and other fields. The strategic offensive role of a navy is projection of force into areas beyond a country's shores (for example, to protect sea
-lanes, deter or confront pirates, ferry troops, or attack other navies, ports, or shore installations). The strategic defensive purpose of a navy is to frustrate seaborne projection-of-force by enemies. The strategic task of the navy also may incorporate nuclear deterrence by use of submarine-launched ballistic missiles. Naval operations can be broadly divided between riverine and littoral applications (brown-water navy), open-ocean applications (blue-water navy), and something in between (green-water navy