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.
Sea going vessels were often mounted with a dragon or serpents head on the prow. The dragon head was simply to frighten away sea monsters and spirits. When approaching land the head could be removed to prevent scaring off the friendly land spirits