The first mention of a dromon is encountered in the biography of a king of East Goths (540s A. D.). More detailed description of a ship gave us Leon Philosopher (the 9th century). The length of some ships of such a type reached 41 m. The planking was made of oak wood with the traditional for peoples of North Europe clincke-built type. Platform at the edges of the vessel were closed by warriors' shields and were intended for bow- and sling men. The steering oar had a support at one point around which it could rotate with the help of a handle placed at a straight angle to the blade of the oar. Installment of the second inclined to the stem masts was a significant step forward at that time. The more narrow sail of the ship allowed her to move at side winds. These types of vessels had a lot of denominations: wholks, naves, nafs, busas, keels. The construction of such a type of vessels allowed shipbuilders to create another widely used type of a Baltic vessel - the Ganza kogg.