Blue Water Navy

A navy able to sustain operations across the open ocean far from home ports, projecting and maintaining force on the high seas (UNCLOS Part VII). Blue-water reach requires underway replenishment, organic air cover, and afloat logistics rather than shore basing. The term contrasts with green-water (littoral and adjacent-sea) and brown-water (riverine and coastal) navies. By common analyst measure only a few fleets, led by the US Navy with its carrier strike groups, qualify as fully blue-water; the PLA Navy is widely assessed as transitioning toward that reach.