King Valdemar's Sailing Route
In the 13th century the main sailing route in the Baltic Sea was written down. This itinerary is preserved in a handwriting called Liber Census Daniae or kung Valdemars jordebog, after the Danish king. The actual sailing route is called king Valdemar's sailing route. It is the oldest existing description of its kind. The text lists several place names, believed to have been pilot stations. The route went close to the coast of the mainland. Perhaps this was in order to profit from the sea breeze. Perhaps it was because the oldest ships used oars rather than sail. Nobody knows. Not until the 14th century, deep-sea offshore shipping became common, using large cogs and navigating with the newly-invented compass.
It is presumed that prehistoric sailing routes went more or less along king Valdemar's sailing route.
The text is in Latin but the place names are written with old Norse spelling. Almost all places have been identified.
The route starts at Utlängan in South Sweden near Denmark. It continues along the Baltic coast to the Stockholm archipelago. Finally it passes Åland, south Finland and ends in Reval (Tallinn, Estonia).
Presently an effort is made to investigate the old route more closely. The Aluett expedition in 1996 was a small part of this project.
One problem for modern sailors is that the old route is partially impossible to follow. The reason is the continuous land rise around the Baltic Sea.
During the last ice age, that ended about 10,000 years ago, Scandinavia had been depressed by billions of tons of ice. When the heavy ice was gone, the land started to rise. It still rises very slowly. The present land rise is about 15 to 40 cm per century, depending on where you are. The rate is highest in the north.
This also means that old wrecks and underwater finds in the Baltic Sea, are not at the same depth as when they sank. One example is the Södertörn area.
Per Åkesson, Feb 1999
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