Clinker built (also known as lapstrake) is a method of boat building where the edges of hull planks overlap, called a land. In craft of any size planks are also joined end to end into a strake. The technique developed in northern Europe and was successfully used by the Vikings and typical for the Hanseaticcog.
A contrasting method, where plank edges are butted smoothly seam to seam, is known as carvel construction.
Examples of clinker-built boats directly descended from those of Viking shipbuilders are the traditional round-bottomed Thames skiffs of the River Thames, and the larger, (originally) cargo-carrying Norfolk wherries of England.