US Navy
U.S. Navy and Japan Maritime Self-Defense Force ships steam in formation during their military maneuver exercise known as Keen Sword 15 in the sea south of Japan, in this November 19, 2014.
Since the sea was navigable, it has been contested, and the ability to project strength across oceans is a defining feature of any world power.
The list below, based on data compiled in Global Firepower's 2018 Military Strength Ranking, ranks countries solely by the number of naval assets they have, including support craft, patrol boats, corvettes, destroyers, frigates, and aircraft carriers - the latter of which refers to both traditional carriers and "helicopter carrier" warships.
A few of the countries that made the list are surprising, and represent naval power all over the world. Check out the 10 biggest navies below: