Bowline on a bight advocate the use of a figure eight twisted version of the Bowline on a bight. This knot can be used to provide a toe hold in the middle of a rope; to make an emergency bosun's chair; and to create an upper rope "block" to make a crude purchase by threading the rope round an anchor point and then back up through the loop. It is sometimes used in sport climbing to tie into two anchor bolts independently. This knot is convenient when a dependable loop is required but neither end of the line is available. It's also commonly used
Sheet bend Sheet bend The sheet bend (also known as becket bend, weaver's knot and weaver's hitch) is a bend. It is practical for joining lines of different diameter or rigidity. It is quick and easy to tie, and is considered so essential it is the first knot given in the "Ashley Book of Knots". Additionally, it is one of the six knots given in the International Guild of Knot Tyers' Six Knot Challenge, along with the clove hitch, bowline, reef knot (square knot), round turn and two half-hitches, and sheepshank. The sheet bend is related in structure to the bowline; like