Early Navigation in the North Sea – The Use of the Lead and Line and other Navigation Methods

Abstract

Every sailor, at the back of his or her mind, is aware that the nearest land is likely to be directly beneath the ship's keel and he or she is interested to know just how near. For over two thousand years, mariners measured depth of water by using a sounding rod in shallow areas and the lead and line in deeper water. This paper considers how, during the "Dark Ages", sailors in the North Sea might have navigated, including the use of sounding rods and lead lines for way-finding during a time when no other navigational instruments were available. Because of the lack of contemporary records the authors firstly consider the use of depth finding in earlier and later times to shed light on how the early North Sea sailors might have operated. The latter part of this paper takes account of the earlier discussion, together with some records of North Sea voyaging, to suggest how "Dark Age" sailors might have used sounding rods, the lead and line, and other techniques to navigate around and across the North Sea.K E Y WO R D S 1. Lead Line.

Accuracy of the hypothetical sky-polarimetric Viking navigation versus sky conditions: revealing solar elevations and cloudinesses favourable for this navigation method

“…If the navigator measured and corrected his orientation several times a day with equal temporal distribution in the forenoon and the afternoon, the North uncertainties averaged for the whole day should be relatively small due to the opposite sign of forenoon and afternoon North uncertainties (figures [3][4][5][6]. This is in accordance with the earlier findings [12] that in sunshine (when the Viking sun compass is easy to use in direct sunlight), it was worthwhile for the Vikings to orient themselves regularly, several times a day during their sailing routes.…”

“…Using easily recognizable coastal places and other simple aids [1][2][3], the Vikings discovered new areas between the ninth and thirteenth centuries like Iceland, Greenland and the coast of North America. In the North Atlantic region, they established colonies that were connected to the European continent through permanent trading routes when the seawater was free of ice [4][5][6].…”