30/12/2022
The elements of maritime geography are loosely defined and their meanings have changed throughout history. The US's 2010 Naval Operations Concept defines blue water as "the open ocean", green water as "coastal waters, ports and harbors", and brown water as "navigable rivers and their estuaries".[2] Robert Rubel of the US Naval War College includes bays in his definition of brown water,[3] and in the past US military commentators have extended brown water out to 100 nautical miles (190 km) from shore.[4]
During the Cold War, green water denoted those areas of ocean in which naval forces might encounter land-based aircraft.[3] The development of long-range bombers with anti-ship missiles turned most of the oceans to "green" and the term all but disappeared.[3] After the Cold War, US amphibious task forces were sometimes referred to as the green-water navy, in contrast to the blue-water carrier battle groups.[5] This distinction disappeared as increasing threats in coastal waters forced the amphibious ships further offshore, delivering assaults by helicopter and tiltrotor from over the horizon. This prompted the development of ships designed to operate in such waters – the Zumwalt-class destroyer and the littoral combat ships; modeling has suggested that current NATO frigates are vulnerable to swarms of 4-8 small boats in green water.[6] Rubel has proposed redefining green water as those areas of ocean which are too dangerous for high-value units, requiring offensive power to be dispersed into smaller vessels such as submarines that can use stealth and other characteristics to survive.[3] Under his scheme, brown water would be zones in which ocean-going units could not operate at all, including rivers, minefields, straits, and other choke points.[3]
As the preeminent blue-water navy of the early 21st century, the US Navy is able to define maritime geography in terms of offensive action in the home waters of its enemies, without being constrained by logistics. This is not true for most other navies, whose supply chains and air cover typically limit them to power projection within a few hundred kilometers of home territory. A number of countries are working on overcoming these constraints. Other authors have started to apply the term "green-water navy" to any national navy that has ocean-going ships but lacks the logistical support needed for a blue-water navy. It is often not clear what they mean, as the term is used without consistency or precision.
A green-water navy does not mean that the individual ships of the fleet are unable to function away from the coast or in open ocean: instead, it suggests that due to logistical reasons they are unable to be deployed for lengthy periods and must have aid from other countries to sustain long term deployments. Also, the term "green-water navy" is subjective as numerous countries that do not have a true green-water navy maintain naval forces that are on par with countries that are recognized as having green-water navies. For example, the German Navy has near the same capability as the Canadian Navy but is not recognized as a true green-water navy. Another example is the Portuguese Navy that, despite being usually classified as a minor navy, has several times conducted sustained operations in faraway regions typical of the green-water navies. However, the differences between blue-water navies and brown or green-water navies are usually quite noticeable, for example, the US Navy was able to quickly respond to the disappearance of Malaysia Airlines Flight 370 and continue operations in the region with relative ease even though the search area covered the Indian Ocean. In contrast, in 2005 the then green-water Russian Navy was unable to properly respond when its AS-28 rescue vehicle became tangled in undersea cables unable to surface, relying on the blue-water Royal Navy to respond and carry out the rescue in time.[7]
Just as nations build up naval capability, some lose it. For example, the Austro-Hungarian Navy was a modern green water navy of the time, but as the countries lost their coasts during World War I, their navies were confiscated, and their ports became parts of Italy and Yugoslavia. The Axis powers lost naval capabilities after their defeat in World War II, with most of Japan's Imperial Navy and Germany's Navy being disarmed and their troop and ship numbers capped and monitored by the Allies. The collapse of the USSR also brought with it the collapse of the second-largest naval force in the world, and the largest submarine force in the world. Although the Russian Federation made sure to inherit the most capable ships, passing most older models to successor states, as it had lost the logistical capabilities of the Soviet Navy, it was no longer able to operate away from Russian shores for extended periods of time. Moreover, budget cuts forced large cuts in the submarine force, such as the retirements of the Typhoon-class submarine. As the Soviet Navy was built largely around submarine warfare the losses in the submarine capability have adversely affected the capability of the newly formed Russian Navy as well.
Examples
List of green-water navies (green) and blue-water navies (blue)
Australia
HMAS Canberra
The Royal Australian Navy is well established as a green-water navy.[8][9] The navy sustains a broad range of maritime operations, from the Middle East to the Pacific Ocean, often as part of international or allied coalitions.[10] The RAN operates a modern fleet, consisting of destroyers, frigates, conventional submarines as well as an emerging amphibious and power projection capability based on the commissioning of HMAS Choules and two Canberra-class landing helicopter docks.[11]
Carrier / Amphibious capability – 27,000 tonne HMAS Canberra and HMAS Adelaide
Amphibious capability – 16,190 tonne HMAS Choules.
