The navy can also be referred to as maritime force. It is the part of a military that operates on the sea, with fleets of military ships, from battle cruisers to destroyers to aircraft carriers. The navy is a branch of the army that is concerned with amphibious warfare, which, put simply, is fighting wars on the high sea. This is the principal function of a country’s navy. Some of these functions can be carried out from on top a surface vessel or from within a submarine several leagues beneath the sea. These functions are also carried out from naval bases that are land based. Beyond active military operations in terms of engaging the opposition, the navy is also involved in a host of other ancillary operations, communications and trainings, which can be carried out from their sea based vessels or their land bases. The navy is responsible for ensuring the security and safety of shipping lanes.  In some cases, they are responsible for ferrying troops and equipment from one part of the world to another, which makes them a very integral part of a nation’s projection of power.


Projection of power is one of the navy’s more strategic roles. The navy is able to convey military power and might to an opposition country’s shore. Also, they can function in reverse, inhibiting an opposing country’s projection of power. The navy is also tasked with the responsibility of offering nuclear deterrence capability to a country’s army, by operating submarines that are able to launch ballistic missiles from underneath the sea. Still on the strategic importance or functions of a navy, these functions can be broadly classified into three: Riverine operations, open-ocean operations, and operations between the first two. The riverine operations or applications are referred to as brown-water navy. Open-ocean operations are referred to as blue-water navy. While, the operation that is midway between the first two is referred to as green-water navy. Most countries see the term “naval” as an all-embracing term for both military and the coast guard forces.


As with all other arms of military operations, naval warfare began with man’s desire to sail the seas. This is evidenced by the fact that even before the invention of long range weapons aboard ships, like canons and the likes, naval warfare was majorly carried out by ramming the opposition and invading their ship—which is termed “boarding actions”. The warships of this era were long and narrow, which were specifically contrived to destroy enemy vessels. These warships were usually driven by oarsmen. This continued through the Middle Age until cannons were incorporated into naval vessels. These cannons were reusable and had fast reloading times. Between the year 300BC and the year 1297 AD, the Chola Dynasty were the rulers of the sea. This Indian born dynasty had the greatest naval military power in the entire world at the time. Their navy was instrumental in helping the Chola dynasty in its conquest to expand its kingdom, leading to the fall of the Sri Lanka islands among a host of sovereign states in South East Asia. They were also instrumental in cutting off piracy in the region.


The 16th and 17th centuries were dominated by Spanish and Portuguese navies, and naval warfare was revolutionized when the English fleet were able to repel the Spanish Armada in 1588. However, this led the Spanish navy to conduct a major overhaul of their fleet, adopting some of the English navy’s ingenuity. This ultimately led to a far greater Spanish navy. Towards the middle of the 17th century, the Dutch were able to take over the Spanish position as the most dominant naval force in the world. The deciding battle was the Battle of the Downs, where the Dutch navy soundly defeated the Spanish navy, ending the Spaniards long reign over the seas.


The next level of evolution in the war for the sea was the introduction of metal plating in the design of ships. This required the use of steam engines and began an arms race between contending navies. By the 19th century, the first submarine was designed, and by the end of the First World War the submarine had become an incredibly powerful and often times decisive addition to the naval fleet. A major shift in naval warfare occurred with the invention of aircraft carriers, which was first used at Taranto (1940) and Pearl Harbor (1941). By the Second World War, the United States became the most powerful navy in the entire world, and their power rapidly increased even through the 20th century into the 21st century.


Naval operations are usually conducted from naval bases. A naval base is typically a port that has been specially constructed to support naval operations. These ports include munitions depots as well as housing for officers and docks for ships and boats. They also include facilities to conduct various kinds of repairs. The navy has the ability to temporarily construct bases near strategic locations during war time. Ships in the navy can operate singly or as part of a fleet. A fleet of ships has a flagship upon which the commander of the fleet is based. The flagship is typically the most powerful ship of the fleet. Blue-water navy is the application of naval power in the open ocean. A blue-water navy has the capability of carrying out operations very far from its home base. In this case, it is able to operate for long periods of time without having to return to base. Some of the vessels in this type of navy are nuclear powered to reduce refueling time. On the other hand, brown-water navy operate near home base, especially in coastal waters. Green-water navy exists in-between. This kind of navy is used as a means of regional power projection.


According to naval tradition, a ship needs to be commissioned before becoming operational. And they are referred to as ships as opposed to vessels. Although, submarines are referred to as boats. For a long time, women were not allowed upon ships, even though ships were referred to as “she”. The reason for this was that they were believed to invite terrible storms during sailing.