Two square sails mounted like an A-frame house.
Imagine a stunt kite shaped like a square. About a meter square. Imagine 128 of these squares attached by just there corners. Each with the front corner of the kite pointing forward. Now attach this square of 128 stunt kites to the boom at top of the mast. Then attach the bottom of this square of 128 stunt kites to each of the oars that they line up with. At the point on the oar just into the blade where there is a hole on the oars from the Oseberg. Now do the same thing on the other side.
You now have 256 stunt kites all pointing straight toward the front of the ship. Thus their orentation to the wind is determined only by the orentation of the ship to the wind.
It makes for a very quick boat.
Will it work? If stunt kites can move fast in the sky this sail design will work. It looks great too. With the red and white squares.