Knot cavers, arborists, rescue professionals, stagehands, fishermen, linemen and surgeons. The International Guild of Knot Tyers is an organization dedicated to the Promotion of Knot tying. Truckers in need of securing a load may use a trucker's hitch, gaining mechanical advantage. Knots can save spelunkers from being buried under rock. Many knots can also be used as makeshift tools, for example, the bowline can be used as a rescue loop, and the munter hitch can be used for belaying. The diamond hitch was widely used to tie packages on to donkeys and mules. In hazardous environments such as mountains, knots are
Overhand knot There are a number of ways to tie the Overhand knot. In heraldry, the overhand knot is known as a "Stafford knot", owing to a representation of it being used first as a heraldic badge by the Earls of Stafford, and later as a general symbol of Staffordshire. As a defensive measure, hagfishes, which resemble eels, produce large volumes of thick slime when disturbed. A hagfish can remove the excess slime, which can suffocate it in a matter of minutes, by tying its own body into an overhand knot, then sliding the knot from its head down to the tail.