A Yosemite Bowline "can be" a very secure loop knot when tied correctly, and is a version of the Bowline with the free end wrapped around one leg of the loop and tucked back through the knot, commonly known as a "Yosemite finish."
In addition to potentially being more secure than a standard bowline, the Yosemite variant is also easier to untie after a load. Some climbers make use of the advantages it offers over other knots in using the knot as an alternative tie-in to the Figure Eight, and to secure heavy loads such as haul bags. But the Yosemite Finish requires very careful diligence in getting the knot right. Tied incorrectly all benefits are lost and it is is a disaster waiting to happen
The downside to the Yosemite Bowline is that it is more difficult to visually inspect than the Figure Eight. It was a Yosemite Bowline that was used by Lynn Hill in France, which failed, due most likely to being improperly tied or tightened, causing her to careen 70 feet to the base of the climb. Be sure to practice the Yosemite Bowline and in particular the tightening of the knot many times before trusting it with your life.
Yosemite Bowline Knot Tying Instructions
- First, tie a regular Bowline with a little longer working end: Lay the rope across your left hand with the free end hanging down. Form a small overhand loop in the line in your hand.
- Bring the free end up to and pass through the loop from the under side ("the rabbit comes out of the hole") and wrap line around standing line ("around the tree").
- Feed line back down through the loop ("the rabbit goes back down the hole"). That completes the regular Bowline.
- Now wrap tag end around the front of the loop and follow exactly the path of the standing line up through the top eye, finishing on the right side of the standing line as you look at the knot from the front.
- The tightening of this knot must be done exactly right to set it in the right order. To do that, take the standing part and the bottom of the loop and pull tight. That tightens the original Bowline (which must be done first!). Then tug on the working end to tighten the Yosemite Finish.
- If you were to tighten the knot with the working end first you actually lose the original bowline and the knot is something completely different and is not a secure knot at all!
- Summary - to gain the benefits of the Yosemite Finish, it must be tied carefully and correctly. Whether it's benefits are worth the risk of tying incorrectly, is debated among climbers. Many climbers do not trust using this knot with their life.