The (modern) Aran version of the lightweight boat called the "currach" (Aran Islands Dialect: "kørəx, korəx") is made from canvas stretched over a sparse skeleton of thin laths, then covered in tar. It is designed to withstand the very rough seas that are typical of islands that face the open Atlantic. Indeed, the Aran fishermen are said to not learn to swim, since they would certainly not survive any sea that swamped a "currach", so it would be better to drown quickly. Despite the undoubted strength of these boats, they are very vulnerable to puncture.