blown off course

{{Short description|Diverted from intended path by unexpected wind}}

To be blown off course in the sailing ship era meant be to diverted by unexpected winds, getting lost possibly to shipwreck or to a new destination. In the ancient world, this was especially a great danger before the maturation of the Maritime Silk Road in the Early Middle Ages, finding expression in the writing of Cosmas Indicopleustes.{{Cite book|url=https://books.google.com/books?id=k2d9DwAAQBAJ&pg=PA45|title=Rome and the Indian Ocean Trade from Augustus to the Early Third Century CE|last=Cobb|first=Matthew A.|date=2018-07-26|publisher=BRILL|isbn=9789004376571|pages=45|language=en}} Even in later eras, the ship could attempt to limit its divergence by tacking or heaving to, but it was often difficult to keep track by mere celestial navigation{{Cite book|url=https://books.google.com/books?id=E2CTAgAAQBAJ&pg=PT793|title=Medieval Italy: An Encyclopedia|last=Kleinhenz|first=Christopher|date=2004-08-02|publisher=Routledge|isbn=9781135948801|pages=763|language=en}} before the invention of the marine chronometer in the late 18th century.{{Cite book|url=https://books.google.com/books?id=lW8DYSPa6fEC&pg=PA17|title=Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time|last=Sobel|first=Dava|date=2010-07-05|publisher=Bloomsbury Publishing USA|isbn=9780802779434|pages=14|language=en}}

A number of "discoveries" during the Age of Discovery were accidentally found in this way,{{Cite book|url=https://books.google.com/books?id=N9DI9rWxowMC&pg=PA15|title=A Cultural History of the Atlantic World, 1250-1820|last=Thornton|first=John K.|date=2012-09-10|publisher=Cambridge University Press|isbn=9780521727341|pages=15|language=en}} and the serendipity of being blown off course is also a trope in fiction. Accidental discovery may have played a larger role than previously acknowledged in early European colonialism in contrast to the idea of a centrally-planned program as by Prince Henry the Navigator, but it is also thought that the Austronesian expansion was more directed and purposeful than once thought, rather than being the result of accidental drift.