Brown-water navy is a term that originated in the United States Navy, referring to the small gunboats and patrol boats used in rivers. The term was coined during the Civil War when Winfield Scott’s Anaconda plan was put into motion. The two pronged plan called fro a blockade of southern ports and then taking control of the Mississippi River.

A broader meaning is any naval force that has the capacity to carry out military operations in river or littoral environments.

Littoral refers to the coast of an ocean or sea, or to the banks of a river, lake or estuary. The littoral zone extends from the high water mark, which may or may not ever be submerged, to shoreline areas that are permanently submerged. It includes the intertidal and sublittoral zones. The word littoral is derived from the Latin noun litus, litoris, meaning shore.

The term is used in contrast to the terms green-water navy and blue-water navy. At one time, it was common to refer to all non blue-water navies as brown-water navy. Today blue-water navies are generally defined as being capable of sustained oversea deployment, preferably with aircraft carriers, while green-water navies are defined as those with frigates or better, operating in coastal and regional area.

The brown-water navy is basically defined as one with patrol boats operating in rivers, lakes, and littoral regions. However, being a brown-water navy does not imply that it lacks offensive capability. Many of today’s small littoral-combat ships are armed with powerful anti-ship missiles.

The US Navy has invested heavily in brown water technology with its current LCS class ship. There are also detachments of Marines patrolling the large rivers of Iraq as well as protecting hydro-electric resources in that country.