I have been having some quite long discussions lately regarding Viking ships, their construction, history and capabilities, and for all you ship modeller buffs, there are quite a large number of websites available that discuss them. But I have found a short video that really demonstrates their differences best at http://www.youtube.com/watch?v=sAtfDO6MArg
Three types of Viking ship are presented, including the Knarr 'Saga Siglar,' the Oseberg/Drakkar 'Dronningen,' and the Gokstad 'Gaia.' Looking at the Knarr, you can see just how round, tubby and high-sided it is in comparison with the large and lean Oseberg, and how the Gokstad has perhaps the best combination of qualities of all three craft. As well, just before the appearance of the 'Dronningen,' there is a Nordlands boat, which is the modern descendant of the Viking ships of old and still in popular use in Northern Norway. The only real difference between a Nordlands and any of the ancient Viking craft is the fact that it has its rudder hung on the sternpost aft (and it is steered by a long pole that goes from the tiller which is still athwartships, to the helmsman who has the pole over his shoulder and pulls or pushes to steer right or left........