A blue-water navy is a maritime force capable of operating globally, essentially across the deep waters of open oceans. While definitions of what actually constitutes such a force vary, there is a requirement for the ability to exercise sea control at long range.
USS Abraham Lincoln leads a formation of ships from eight countries during the Exercise RIMPAC in July 2006.
A blue-water navy still remains susceptible to asymmetric threats, an example being the USS Cole bombing in October 2000.
Indian Navy flotilla of Western Fleet escort INS Vikramaditya (R33) and INS Viraat (R22) in the Arabian Sea; according to the Todd & Lindberg classification system, six navies are considered to be ranks 1-3 blue-water "multi-regional power projection" navies, capable of operating in multiple regions adjacent its own.
Cavour (foreground) operating with Harry S. Truman (middle) and Charles de Gaulle (background) in the Gulf of Oman, 2013
The capital ships of a navy are its most important warships; they are generally the larger ships when compared to other warships in their respective fleet. A capital ship is generally a leading or a primary ship in a naval fleet.
Aircraft carriers form the main capital ships of most modern-era blue-water navies.
Battleships became the main form of capital ship after sailing vessels fell out of use, and remained so up to World War II. Shown is the German SMS Helgoland.
Ships of the line (of battle) were the capital ships of the era of sail. Pictured is the Spanish Santa Ana, a very large example with 112 guns.
British battlecruiser HMS Repulse