The "Great El Niño" lasted from 1789 to 1793, profoundly impacting weather and causing massive droughts. A lesser-known consequence of this climatic event is that it saved the lives of Captain William Bligh and his crew when the mutineers on the HMS Bounty set them adrift in the South Pacific.
El Niño is associated with a period of prolonged warming in the surface temperatures of the Pacific Ocean, accompanied by changes in wind direction and ocean currents. Rains that would normally drench the western Pacific are pushed toward the Americas, causing droughts in such places as India, Australia and Indonesia. Some historians argue that prolonged bad weather and crop failure in Europe during the early stages of the late 18th century El Niño event were partly responsible for the unrest that culminated in the French Revolution.
Written records of El Niño stretch as far back as Peru in 1525. But, global commerce and expanding European empires in the late 1700s provided the first detailed, global accounts of the climatic event. According to a journal article by Australian historian Richard Grove, one source of data that has helped pinpoint the beginning of the Great El Niño was the logbook of the famed HMS Bounty. Temperature readings were made every four hours while at sea, and the lowest and highest temperatures were read while in port. On December 6, 1788, Bligh wrote, while his ship was sheltered at Matavai Bay, Tahiti, that:
I experienced a scene today of Wind and Weather which I never supposed could have been met with in this place. The wind varied from ESE to the NW and the Therm. stood between 78 and 81.5 degrees. By sunset a very high breaking sea ran across Dolphin Bank, and before seven o'clock it made such a way into the Bay that we rode with much difficulty and hazard. Towards midnight it increased still more and we rode until eight in the morning in the midst of a heavy broken sea which frequently came over us. The Wind at times dying away was a great evil to us for the Ship from the tremendous Sea that broke over the reefs to the eastward of Point Venus, producing such an outset thwarting us against the surge....
Those observations indicated that the El Niño episode was already well underway. And, that would prove fortuitous for Captain Bligh, according to Grove:
A few months later the fact that an El Niño was in progress actually saved the life of Bligh and the men who were cast adrift by the mutineers. Instead of the very hot conditions that would normally have confronted the 23-foot open boat between Tofua in the South Pacific and Timor between 29 April and 14 June 1789, Bligh and his men encountered cold conditions throughout the voyage. Furthermore, instead of a dry heat that would probably have been deadly, the rainfall they experienced was so cold that Bligh instructed his men to soak their clothes in warm seawater and then wear the wet clothes to keep warm!
On 11 May Bligh records that 'at noon the sun appeared which gave us as much pleasure as on a winter's day in England'. On 18 June Bligh again records heavy rain, 'which enables us to keep our stock of water up'. The crew all complained of rheumatic pains and cold. Furthermore, the supply of rain- water also allowed Bligh to avoid making lands on small Pacific islands for water, as they might have had to in a normal year. If they had tried to make land it seems likely they might have met a hostile reception and not lived to tell the tale.
Because of El Niño, Grove adds, "the story of Bligh and the Mutiny on the Bounty has entered folklore, instead of merely remaining the 'mystery of the disappearance of Captain Bligh and the Bounty as it almost certainly would have done in a normal year in the South Pacific."