The great sea expeditions of the Viking Age - The basis of the great sea expeditions undertaken by the Vikings was ship technology. The Viking ship was a piece of high technology based upon hundreds of years of development and experience. It was distinguished by its narrow keel and shallow draught. This made even the largest ocean-going warships suitable for sailing onto beaches and up rivers. Such tactics enabled, for example, the siege of Paris to be carried out in the year 885.
"Saga Oseberg" at Roskilde Fjord. The first reconstruction of the Norwegian Oseberg ship sank in just 20 seconds during his first trials in 1987, no one thought afterwards that the ship was even sail skillfully. But reconstructioners from the Viking Ship Museum in Roskilde in 2006 thought that after a meticulous reconstruction, the ship could be resurrected and become able to sail.