bluewater

Bluewater is a term used in several fields to describe deep ocean water, long-distance capability, and freshwater resources. In oceanography and common usage, blue water refers to the open ocean away from coastlines, typically deep and relatively clear, with a characteristic deep blue color resulting from the absorption and scattering of light by seawater.

In hydrology and sustainability, blue water denotes freshwater contained in rivers, lakes, and groundwater that can be withdrawn for human use. It is contrasted with green water, which is soil moisture stored in the root zone used by vegetation. The concept is central to discussions of water footprints, water allocation, and resource management.

In military and naval contexts, a blue-water navy is one capable of operating across the deep oceans and projecting power globally, rather than being limited to littoral or riverine environments. Building a blue-water navy requires advanced ships, aircraft, and supply chains for sustained operations far from home ports.

In sailing and recreational boating, blue-water sailing describes voyages across open oceans, involving long passages and storm conditions. Boats described as blue-water capable are designed for extended offshore travel, with emphasis on reliability, seaworthiness, and self-sufficiency.