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
Yosemite bowline a climber's harness, the figure-of-eight follow through is the most common choice because it is more widely known and more easily checked. "The Mountaineering Handbook" is one of the few texts that suggest that the Yosemite bowline is better for this purpose. Suggested benefits of the bowline include being easier to untie after loading or when wet and frozen, and being possible to tie-in with only one hand. Testing found it a strong knot for the purpose. It is recommended that any knot which is used to attach a rope to a safety harness is always finished with a stopper