Navigation at sea has always been a challenge. People have navigated the oceans and coastlines for hundreds of years using navigation marks and navigation aids. The first sailing marks were natural landmarks such as islands and mountains. Then, cairns were raised to improve the accuracy.
Dangerous skerries were marked with iron poles, and wooden cairns called “båker” were raised in various places. Occasionally, the landmarks were a cross or a windmill.
At sea, the sailors navigated by the sun and the stars. They also learned how to follow the ocean currents and observe the sea life.
When land was in sight, it was important to recognise mountain ranges and landscape formations that would indicate their whereabouts.
Lindesnes was an important landmark. When the sailors were certain the Naize was in sight, they could change course and follow the coastal waterway. They sailed along the coast westwards to Bergen or eastwards.
Heading eastwards, they would change course after reaching Færder and follow the Swedish coast southwards. When land was in sight, they knew their position. Lighthouses like Lindesnes and Færder may be called “tack beacons”. Whenever these were on the horizon, it was time to change course.
In the 17th century, Dutch nautical charts already included land formation maps, which were drawings that depicted the contours of land from an oceanic perspective. The first sea charts were inaccurate, yet still indicated a landscape recognisable today.
The first lighthouses were generally placed where it was common to change course, as at Lindesnes, the tip of Skagen and by Færder. Often, it was cairns and wooden sea marks that had existed for many years, which were replaced by lighthouses.
At open sea, it was almost impossible to determine an accurate position without knowing the latitude or the longitude. The latitude determines how far north or south one is from the Equator. It runs from 0 to 90 degrees. The longitude determines how far east or west one is from the meridian line passing through Greenwich, England.
An approximate latitude can be measured by taking into account the position of the sun according to the horizon. At night, the North Star and other constellations were used to determine the latitude.
The first marine chronometer was constructed and completed by the British mechanic John Harrison in 1730. For 30 years, he improved upon the first models and won several prizes, but he never got the 20 000 British pounds that had been promised the person who solved the “Longitude-problem”.
When the coal-burning beacons at “the Naize” were lit, the safest navigation method was to follow the coast from one point to the next. The Southernmost Cape of Norway was rough, but there were several safe harbours throughout the perilous waters.
Ships that were going to Bergen or towards the Baltic sailed North with a good margin to the Danish west coast and its treacherous sandbanks. Landmarks at Lindesnes made it possible to follow the maritime lanes north or east, and to seek safe harbours for rest and provisions.
The two coal-burning beacon lights provided safe landmarks at night.