The British

The most serious foreign competition came from the British. In the last half of the 18th century, Great Britain was the world's most formidable sea power. The British Navy sent several expeditions around the world. By far, Britain's most accomplished navigator was Captain James Cook, who circumnavigated the globe twice. Cook found and mapped many Pacific islands, including Hawaii. He learned how to treat scurvy, even though he did not know what caused it. He tested the first clock that kept accurate time over a long sea voyage, which made it possible for mariners to know their longitude - their position east and west on a globe.

In 1776, the British Navy called Cook out of retirement and sent him on a third global voyage, this time to the Pacific Northwest Coast. He was directed to search for the Northwest Passage, a water route from the Pacific to the Atlantic Ocean around North America. If such a route were found, it would provide a much shorter alternative to sailing around South America. He was also to report on the activities of the Spanish and Russians in the region.