Livestock, such as young pigs, had to be transported to and from the Aran islands using boats. These currachs were light-weight boats made from canvas stretched over a skeleton of wooden lathes, and then covered in tar. Large animals such as cattle or horses, being brought to market or moved for summer grazing on the mainland, had to be hoisted on board a hooker (a larger sailing boat) using rope slings to lower them from the edge of the pier. If the tide was too low the animals were tethered to the back of a currach and towed, swimming, out to the hooker.