What was the vikings mode of transportation and why was it.

 The vikings had cogs or trade ships and they had longships. The longships were long and narrow with many small rooms for tools and weapons. They could not only run before the wind but could run across the wind better than most ships of the time. The vikings longships were truly the reason to their success. They needed the longships because vikings had to get to the place they were raiding and then get away after the raid before the the other army got there. 

         The longest longship found was the long dragon. It was 140 feet long (now we know they called them longships). The vikings claim that there was one twice that size. The longships were not only sea worthy but could go in shallow waters. Docks were also unecessary the vikings just dragged them up on the shore, which i think would be relatively hard.