The term Viking Vessel is a reference to the type of ship used by the Vikings during their travels and raids. The crossword solution for this term is Longship, which is an 8-letter word. Longships were the vessels used by the Vikings for their voyages and were characterized by their long and narrow shape, shallow draft, and high speed. They were also equipped with a single square sail and oars, allowing them to navigate both open seas and shallow rivers.