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
Axle hitch which case a double bowline or water bowline should be used as the security knot. Axle hitch The axle hitch is used to tie a hitch in a hard-to-reach place, or for extra security by having a double hold on an object. When the initial bight is passed around the object, the rest of the knot can be completed out away from the cramped location. The knot is finished with a bowline knot or other reliable knot that connects the working end to the standing part. It provides distributed strength and is useful when a shock load needs to be