Vistula Spit
The Chronicon terrae Prussiae describes the founding of Elbing under the leadership of Hermann Balk. After building two ships, the Pilgerim (Pilgrim) and the Vridelant (Friedland), with the assistance of Margrave Henry III of Margraviate of Meissen, the Teutonic Knights used them to clear the Vistula Lagoon ("Frisches Haff") and the Vistula Spit of Prussians: