Longship

The very popular Viking longship (used about 800 AD) was actually not very high, it was stable, open galley with long bows and sterns and a row of oars down each part - left and right. Longships were long and narrow (hence the name), and of shallow draft, so that they could be taken ashore fast and easily. Similarly to all ships of Northern Europe for about five centuries, they were "clinker" built - that is, constructed of planks that go one over the other, built with iron nails and stuck with tarred rope - and had a single, large square sail. A single side rudder on the starboard quarter was used for navigation and steering. A necessity in the difficult northern waters, longships were limited in warfare, however, and were used only as trade ships.
The smallest longships were sometimes called "knarr". The typical longship had up to 60 rowers. It was very moveable, maneuverable and at the same time fast; good also for battle. The biggest Viking vessel, the "drakkar" (or dragon ship) used more than 60 rowers. However, they were only a few, because they were expensive to build, although irreplacable in battle. They were used mostly by royal and VIP persons.
In Norway was found the most famous and most well preserved Viking ship called Gokstad, built about 900 AD. It is 25 m long and 5 m wide.
To the end of 13th century, clinker ships were extensively used in England and the Isles. They were one-masted square-rigged based on the Viking long ship. The Bayeux Tapestry, shows some ships used by William the Conqueror to invade England in 1066 - the scale can be seen; also parts of the design.