Background

Navigation
“Navigation is that excellent Art, which demonstrateth by infallible conclusions, how a sufficient Ship may be conducted the shortest good way from place to place, by Table and Taravers.”
JOHN DAVIS. August, 1594.


Golden Hind – Forbes 16th Century map - Karinelli
Since the beginning of time man has been trying to develop and refine a reliable method of telling where he was on the earth and how to safely reach and return from far flung destinations. This knowledge often meant survival or an increase in trade and military power: early cultures are thought to have begun the process by marking their hunting trails. As cultures became more sophisticated and gained greater knowledge of their surroundings, they began to use observations of the sky and other natural phenomenon to guide them.

Astronomers from Egypt and Greece made significant contributions to their developing science which eventually became the basis of our modern navigation techniques which use latitude and longitude to accurately describe a position on the Earths surface. Methods of navigation relying on observation and measurement of which were extensively used until the advent of the satellite based GPS or Global Positioning System.
Pyramids and Sphinx – Tiffx1

Early mariners followed the coast closely and only ventured to sea as they developed the necessary navigation skills.
The Phoenicians used the North Star to guide them in their voyages, while the Polynesian peoples were undertaking long distance voyages across the pacific using the wave patterns, stars and birds to guide them towards their destinations.
Hawaiian Canoe- Wilderness family
Further developments occurred with the arrival of the magnetic compass (credited to China) to indicate your “heading” and the sextant which uses adjustable mirrors to measure the exact angle of the sun and planets above the horizon. These “sights” are then used in combination with a nautical almanac to determine your latitude.
It was not until the 1761 that longitude was able to be measured accurately with the aid of John Harrison’s chronometer which kept accurate time to within 1 second a day. Chronometers and sextants were used to determine latitude and longitude for the two centuries.
Deck watch - 400 day Clock


During World War II several radio based navigation systems were widely employed by both aircraft and shipping, however they had limitations and were eventually replaced by GPS.
GPS is extremely accurate and has the capacity to define your position to within a metre, by triangulating bearings from the GPS unit to a system of 24 satellites orbiting the earth.
GPS track - adantus