<P> Though Columbus was wrong about the number of degrees of longitude that separated Europe from the Far East and about the distance that each degree represented, he did possess valuable knowledge about the trade winds, which would prove to be the key to his successful navigation of the Atlantic Ocean . During his first voyage in 1492, the brisk trade winds from the east, commonly called "easterlies", propelled Columbus's fleet for five weeks, from the Canary Islands to The Bahamas . The precise first land sighting and landing point was San Salvador Island . To return to Spain against this prevailing wind would have required several months of an arduous sailing technique, called beating, during which food and drinkable water would probably have been exhausted . </P> <P> Instead, Columbus returned home by following the curving trade winds northeastward to the middle latitudes of the North Atlantic, where he was able to catch the "westerlies" that blow eastward to the coast of Western Europe . There, in turn, the winds curve southward towards the Iberian Peninsula . </P> <P> It is unclear whether Columbus learned about the winds from his own sailing experience or if he had heard about them from others . The corresponding technique for efficient travel in the Atlantic appears to have been exploited first by the Portuguese, who referred to it as the Volta do mar ("turn of the sea"). Columbus's knowledge of the Atlantic wind patterns was, however, imperfect at the time of his first voyage . By sailing directly due west from the Canary Islands during hurricane season, skirting the so - called horse latitudes of the mid-Atlantic, Columbus risked either being becalmed or running into a tropical cyclone, both of which, by chance, he avoided . </P> <P> In 1485, Columbus presented his plans to King John II of Portugal . He proposed that the king equip three sturdy ships and grant Columbus one year's time to sail out into the Atlantic, search for a western route to the Orient, and return . Columbus also requested he be made "Great Admiral of the Ocean", appointed governor of any and all lands he discovered, and given one - tenth of all revenue from those lands . The king submitted Columbus's proposal to his experts, who rejected it . It was their considered opinion that Columbus's estimation of a travel distance of 2,400 miles (3,860 km) was, in fact, far too low . </P>

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