For centuries, the naval forces of countries have influenced battles fought on land, sea, and in the air. This goes to show that the power of the navy cannot be discounted even if you aren't fighting in open water. They are able to give fire support, command-and-control, and even insertion and extraction support for ground forces. These vessels can literally pound an area into dust.

The biggest ship out there would have to be the aircraft carrier. They are nuclear-powered monsters that can hold and launch different kinds of aircraft. They can also be used as staging points for infantry assaults as they can perform command duties. The people aboard such a vessel learn their own language so that they can communicate efficiently under pressure. They use custom flags to communicate with each other over long distances. They have specific patterns for waving the flag around as well as specific colors that mean different things. This system minimizes the chances of something going wrong. Especially since everything that happens aboard the vessel is dangerous.

An aircraft carrier is a great symbol of power and control over a certain region. This means that whoever controls the vessel is handling a huge amount of power. In essence, the vessel itself is a weapon of intimidation that could potentially force your opponents to surrender without actually having to engage them in combat. The effect is magnified when they spot the world flag of the country that owns the aircraft carrier since they know that their opponent has that kind of capability.