"Partner in the brown water; secure the green water; own the blue water," is a colorful new Navy mantra. It refers to the need to work closely with other nations to operate in the riverine and sea-land interface environment, to ensure access in the littoral and to maintain dominance in the open ocean — or blue water — environment. Although the Navy will operate closer to shore, it will not cede supremacy of the high seas. And although potential adversaries are not vying for open ocean superiority today, one cannot assume that will be the case in the future.

http://www.armedforcesjournal.com/2007/04/2559195