Harrison 's solution revolutionized navigation and greatly increased the safety of long-distance sea travel . The problem he solved was considered so important following the Scilly naval disaster of 1707 that the British Parliament offered financial rewards of up to £ 20,000 ( equivalent to £ in ) under the 1714 Longitude Act . In 1730 , Harrison presented his first design , and worked over many years on improved designs , making several advances in time-keeping technology , finally turning to what were called sea watches . Harrison gained support from the Longitude Board in building and testing his designs . Toward the end of his life , he received recognition and a reward from Parliament . Harrison came 39th in the BBC 's 2002 public poll of the 100 Greatest Britons
Scilly naval disaster of 1707
Scilly naval disaster of 1707
John Harrison