Brown-water navy in the context of "Navy"

Naval warfare is combat in and on the sea, the ocean, or any other battlespace involving a major body of water such as a large lake or wide river.

The armed forces branch designated for naval warfare is a navy. Naval operations can be broadly divided into riverine/littoral applications (brown-water navy), open-ocean applications (blue-water navy), between riverine/littoral and open-ocean applications (green-water navy), although these distinctions are more about strategic scope than tactical or operational division. The strategic offensive purpose of naval warfare is projection of force by water, and its strategic defensive purpose is to challenge the similar projection of force by enemies.

A blue-water navy is a maritime force capable of operating globally, essentially across the deep waters of open oceans. While definitions of what actually constitutes such a force vary, there is a requirement for the ability to exercise sea control at long range.

The term "blue-water navy" is a maritime geographical term in contrast with "brown-water navy" (littoral waters and near to shore) and "green-water navy" (near to shore and open oceans).

A green-water navy is a maritime force that is capable of operating in its state's littoral zones and has limited competency to operate in the surrounding marginal seas. It is a relatively new term, and has been created to better distinguish, and add nuance, between two long-standing descriptors: blue-water navy (deep waters of open oceans) and brown-water navy (inland waters, littoral and shallow seas).

As a non-doctrinal term with no concrete legal or political definition, it can be used in several different ways. It originated with the United States Navy, who use it to refer to the portion of their fleet that specializes in offensive operations in coastal waters. Nowadays such ships rely on stealth or speed to avoid destruction by shore batteries or land-based aircraft.