Cog

The cog was a single-masted, square-rigged, clinker-built cargo carrier that dominated the high-medieval Baltic and North Sea trade, especially under the Hanseatic League from the twelfth to fourteenth centuries. Its flat bottom let it sit upright on tidal flats to load, and its high freeboard and stern rudder made it a capable bulk carrier of grain, salt, cloth, and timber. The Bremen cog of about 1380, raised from the Weser in 1962, is the best-preserved example and anchors the study of medieval ship construction.