Late 17th century to the present
At the beginning of this era, the ideas of the Enlightenment challenged traditional ideas about political legitimacy and led to the American and French Revolutions. The Industrial Revolution transformed the social and economic foundations of people’s lives, and created the need for vast amounts of raw material and markets in which to sell manufactured goods. A new wave of imperialism swept the globe and had a major impact on Asia and Africa. Challenged by the new changes in economic and political thought, long standing civilizations struggled between reforming their ways and retaining their traditional identities. As states industrialized, they expanded their existing overseas colonies and established new types of colonies and transoceanic empires. The growth of these new empires challenged the power of existing land-based empires of Eurasia. New ideas about nationalism, race, gender, class, and culture not only facilitated the spread of these transoceanic empires, but also justified anti-imperial resistance and the formation of new national identities.
Initially, vessels of this period continued to be built of wood and powered by sail and oar. By the nineteenth and twentieth centuries new materials such as steel and man-made materials were used in the construction of ships which were powered by steam, various fossil fuels, and even atomic reactors. Nineteenth century navigation benefited from more accurate charts, factory-produced high quality tools, and accurate oceanographic and weather data which became more accessible and affordable. The twentieth century was the age of electronic navigation which made celestial navigation almost obsolete. New tools were developed. They included the radio, the gyroscopic compass, shipborne radar, Long Range Navigation (LORAN) System, and the Global Positioning System (GPS). As humanity began to explore the ocean depths the Remotely Operated Vehicle (ROV), and Sound Navigation and Ranging (SONAR) were added to the tool chest. Underwater vehicles were also developed. They included the Alvin (a manned deep sea submersible) and the Tektite which is technically not a vehicle but a submerged, manned laboratory.