The rethreaded figure-of-eight is an essential knot for tieing a rope onto a climbing harness. It’s easy to tie, very strong and easy to spot if tied incorrectly. It’ll be the first knot you’re taught at Geckos and will hold you in good stead. Here’s a short video showing how to do it:
Here’s a slightly longer video, demonstrating both how to tie the figure-of-eight and its advantages:
An alternative is to use the bowline knot (you may already know this from sailing). Its major advantage is that it’s easier to untie than the figure-of-eight. However, it’s less foolproof AND MUST ALWAYS BE SECURED WITH A STOPPER KNOT. For this reason it is only recommended for advanced climbers. We usually teach it to those students who are learning how to lead-climb.
Finally, the Italian, or Munster hitch. A useful knot to know as, when combined with a pear-shaped karabiner, it can be used to belay a climber. Warning- when locking off, the dead rope must be held upwards, in the opposite way to using an ATC. For this reason it’s important to be properly taught when and how to use it.