1989 Suhaili - The Columbus Navigation Experiment

Subsequent to the Golden Globe “Suhaili” had been re-fitted and used for family cruising holidays to Portugal and on the west coast of Scotland until 1989 when she was sailed to America, solo, to test renaissance navigation systems. Using only an Astrolabe(see left) to take the height of the sun at noon, and a “Dutchman’s Log” to calculate the distance travelled, RKJ arrived off San Salvador in the Bahamas from San Sebastian, on Hierro, in the Canaries, some 3,000 miles, only 8 miles out in Latitude and 22 miles out in Longitude. (A Dutchman’s Log” is timing a chip of wood past a known distance along the ship’s hull and then calculating the speed) The Astrolabe was developed by the Greeks, and used extensively for measuring the altitude of a body on land and sea. The one used in this experiment is a copy of a Portuguese astrolabe found near Valencia in Ireland. It was gradually replaced at sea by the Cross staff, Backstaff and later the Octant and Sextant. The average error between the observations taken with the Astrolabe and the Argos satellite tracking system was 14.8 miles. The worst error was some 86 miles, on a day when there was a haze covered sun and the result could not be trusted. Thus a renaissance navigator who had indexed his astrolabe at a port with known latitude (once the Sun’s Declination Tables had been published by the Portuguese in 1485) might expect to make a landfall after an oceanic crossing within sight of a familiar landmark from the masthead. Calculating accurate longitude had to wait the development of accurate time pieces in the eighteenth century. After an uneventful sail to Norfolk, VA, Suhaili set off, with 3 crew, for home but ran into a storm in mid Atlantic. Attempts to stream warps were frustrated by snakes honeymoon (tangle) and on the 4th knockdown the boat was dismasted and the radio disabled. Setting up a jury rig the team sailed to Horta in the Azores and after one attempt to continue their voyage, during which ran ran into more bad weather, Suhaili was laid up in Horta for the winter. Next spring new masts were shipped to Horta, stepped and Suhaili completed her voyage home. Suhaili arrives at Horta under jury rig RKJ received the Gold Medal from the Royal Institute of Navigation for the experiment and the Silk Cut Seamanship award. The book of this voyage “The Columbus Venture” published by BBC Books in 1991, won the book of the sea award. See RIN