Longships

Longships, langskip or drakkar were boats used by the Scandinavians and Saxons for their raids on costal and inland settelments. They were the epitome of Scandinavian military power and ranked extremely as precious material possessions.
The longship was a long, narrow, light boat with shallow draft, with oars along approximately the entire length of the boat. Later versions sported a rectangular sail on a single mast to augment the rowers particularly during longer journeys. In combat the variabilily of wind power made rowers the chief means of propulsion. virtually all longships were clinker built and waterproofed by moss drenched in tar. The ship's low mass and shallow keel permitted navigation in waters just 1 meter deep, rapid beaching when landing on beaches, and portage over land.
Construction
Our best evidence for longship building comes from ship-burials. It was common in Viking society for kings to be buried under a long burial mound in a ship with rich possessions. The Oseberg ship burial in Norway and the Anglo Saxon longship of Sutton Hoo in England are both good examples.
Longships were extraordinarily narrow for their length compared to modern standards The main discovered longship (at Roskilde harbor) is 35m in length, and the longship from Hedeby harbour has the largest length/width proportion: 11.4 to 1. However, later longships, optimized for sailing, had lower ratios, often 1 to 7 or even 1 to 5.
In contrast, Scandinavian trade ships or knarrs were built deeper and broader to accommodate bulkier cargo, and were more reliant on sails. A similar relationship may be seen in Mediterranean galleys, which are now and then called longships as well, and their merchant vessels, which were roundships.
Rectangular sails made of wool strengthened by leather were introduced later. Under sail, longships were very fast, achieving speeds of 14 knots. They were also extremely seaworthy, but, being essentially open boats, not very habitable. However, this did not stop early Scandinavian explorers from discovering and settling in Iceland, Greenland, and Canada, all well before Christopher Columbus landed in the Bahamas in 1492.