Kvalsund ship

The Kvalsund ship (Norwegian: "Kvalsundskipet") is a late 7th century rowing ship, discovered embedded in a marsh on Kvalsund in Herøy, Møre og Romsdal near Ålesund in 1920, along with a smaller rowboat called "Kvalsundferingen". It is of an earlier construction than the Oseberg and Gokstad ship, both of which date to the ninth century. The Kvalsund ship dates to 690AD.
The ship featured a detachable rudder on one side that could be removed in shallow water, and its shape strongly suggests it had a sail - if so, it would be the first Scandinavian ship discovered to have one.