 The three Viking ships in the film were designed using blueprints  for an actual Viking ship salvaged from the water and restored by a  Viking museum in Norway. It turned out that the boats built for the  film were too accurate, because the modern actors were taller than  their historical counterparts. Every other oar hole had to be  plugged so the modern men would have room to row with a full oar  stroke. Otherwise, they would hit the backs of the oarsmen seated in  front of them when pushing the oar handles forward to start each new  stroke.