Comment by deltarholamda

Boat designs change very slowly, so I would bet on his guess. Most changes would be in improvements in smaller technologies, e.g. improved nails, than in major hull shape changes. As I understand it, Vikings did use barge-like boats, but they mostly used the longboat form, and the major change to long boats is to make them longer to carry more, which doesn't change the draft that much.

To my mind, the greater change would have been to sea levels from the 11th century to now, which would alter landing spots more than the boat design.