This paper formed the 1990 Anderson Memorial Lecture and was presented to the Bristol Channel Branch on 22 February. In developing his theme, George King concentrated very much on the characters of the navigators concerned with six extraordinary exploits, but without losing sight of the navigation itself. The following version is necessarily much abridged and the editor has reluctantly omitted the detail of fascinating accounts of the expedition commissioned by Thomas Jefferson to explore the American West, the epic open boat voyage by Ernest Shackleton in the Antarctic in 1916, the first solo air crossing of the Atlantic by Charles Lindbergh in 1927, and the spectacularly successful Apollo 11 mission in 1969. The full text of George King's meticulously researched and brilliantly written paper is available to members from the Institute, price £3.