Green-water navy in the context of "Hellenic 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 navy, naval force, military maritime fleet, war navy, or maritime force is the branch of a state'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 piracy, 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 a 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), although these distinctions are more about strategic scope than tactical or operational division.

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 brown-water navy or riverine navy, in the broadest sense, is a naval force capable of military operations in inland waters (rivers, lakes and inland seas) and nearshores. The term originated in the United States Navy during the American Civil War, when it referred to Union forces patrolling the muddy Mississippi River, and has since been used to describe the small gunboats and patrol boats commonly used in rivers, along with the larger "mother ships" that supported them.

Brown-water navies are typically only used for patrolling and enforcing internal waters, in contrast to blue-water navies, which can independently conduct operations in the open oceans and project power far offshore. Green-water navies, which operate mainly in brackish estuaries, bays and shallow seas not too far off coasts (typically within the bounds of exclusive economic zones), fill the operational gap between brown-water and blue-water navies.