For thousands of years people found their way around the oceans without any charts or instruments. The early Polynesians migrated out across the Pacific from New Guinea using the stars, the sun and swell direction as their guide. Bird flight patterns told them a whole story, and migrating birds led them from island to island across the Pacific. In the same way storks flying across the straits of Gibraltar and the Bosporus demonstrated to the early Mediterranean sailors that these strips of water could easily be crossed. Similarly, wild geese flying away each year across the inhospitable waters of the North Atlantic showed the Vikings the way to Iceland and Greenland and eventually to North America – long before Christopher Columbus landed in the West Indies.  Artic Terns led  the  Portuguese  around the  Cape of Good Hope into the Indian Ocean.   Although these adventurous early seafarers managed almost without instruments or charts or knowledge of latitude and longitude, there were two instruments which did help them find their way.

At some stage, they had discovered that there was one star in the sky that didn’t move through the night. In fact, all the other stars seemed to rotate around it. This was of course the Pole star. They also observed that as they traveled further north, the Pole star got higher in the heavens, and vice versa when they traveled south. When they went to the east or west it stayed the same distance above the horizon. Whether they realized it or not, they were measuring their latitude. Therefore, any device that could record the height of the star above the horizon could be used to find their way back to that same parallel of latitude again.   The first of these crude instruments was what is known now as the ‘Latitude Hook”. It was probably used by the Polynesian sailors. It was a very simple device, consisting of a piece of split bamboo, about 12 inches long with a small loop at the top, and a shorter piece tied crosswise at the bottom.   Obviously this would only work in the Northern Hemisphere, because there isn’t any star in the polar position in the Southern skies. The navigator would have to estimate the position of the South Pole, and well… I can’t imagine the accuracy would be much.

The other instrument, probably used by the Arab navigators was the Kamal. This worked on the same principal. It consisted of a rectangular piece of wood, with a string passed through a hole in its center. The user aligned the pole star with the top, and the horizon with the bottom. He held the string in his teeth, and tied a knot in it at the length corresponding to the correct angle between the pole star and the horizon. This was probably more accurate than the latitude hook mentioned above, as the length of the piece of string stayed constant, whereas the latitude hook depended on how the navigator held his arm.   These instruments didn’t have any measurements marked on them, though with the kamal, the knots in the string were a crude measurement referring to several different locations.   These primitive instruments, without any scale or markings were the great-great-grandfathers of the modern-day sextant. Sadly, even that precision instrument is on the verge of extinction, thanks to the introduction of satellite positioning systems.