Note: when used in climbing applications, the “simple” bowline as shown below in the photos is NOT considered safe unless the tail is backed up in some way. This is typically done with a barrel or overhand knot in the tail. (Having said that, knowing how to tie a bowline is helpful in many different non-climbing applications, even the “simple” version shown here, so it's still a great knot for the tool kit.)

If you want a deep dive into proper application of knots, the Australian Professional Association of Climbing Instructors (PACI) website is a great place to start.

Ah yes, the bowline knot. A favorite of sailors, Boy Scouts, and sometimes climbers, commonly used to tie the free end of the rope around a boulder or tree as a fixed line, or possibly stringing up a tarp.

However, for some reason, this knot is deceptively difficult for many people to tie correctly. (I’ve seen otherwise very experienced climbers screw this knot up on many occasions.)

Many people seem able to tie it properly in a somewhat controlled setting, like practicing it around a table leg. But put them on the other side of the rope, or make them tie it facing a different direction than usual, or some other minor switcheroo, and “knot dyslexia” seems to set in. And, to be honest, I’ve experienced this myself a few times.

Well, there’s a very cool way to tie a bowline that seems to solve all these issues. It’s fast, reasonably idiot proof, and most people find it much easier than the old-school “rabbit comes out of the hole, around the tree and back into the hole” method. And, as with some of the best rope techniques, and there is a bit of rope magic happening that would make you blink and say “Dang, did I just really see that?!”

Pass the end of the rope around your anchor object, here a post.

2) Make a slipknot.

3) Pass the end of the rope through the loop of the slipknot. (Keep the slip knot and loop fairly loose, as you see here.)

4) Tighten the slipknot. It will invert and make a “snap”, then you should magically have a bowline. (Note, for climbing, you need to tie this with a longer tail of a foot or so, so you'd have enough rope to tie a proper backup knot in the tail. But for setting up a tarp, this should be fine)

Yes, you need to try this a few times at half speed to see this sorcery for yourself, it really is sort of a magic trick!

Note: depending on how you feed the free end through the slipknot, the final version of your bowline could be in one of two configurations.

One, you may end up with the free end inside of the loop (as we see above) which is the standard garden-variety bowline. Or, you may end up with the free end outside of the loop, which is known in some circles as a “cowboy bowline.” Even thought knot-nerds love to argue about it, one is not conclusively stronger / better / preferable to the other, so it appears not to really matter which way the tail ends up. You can read more on this discussion here.

“Standard” bowline on left, “cowboy” bowline on right.

As we like to say at Alpine Savvy, most any sort of hands on skill like learning a knot is a better show than a tell.

Here’s a short video that shows you how to do it. First example is around your waist, second example is around a tree. (There's probably some crazy rescue scenario that I hope never to be involved in that might require someone lowering a rope down, and me tying it around my waist like this. Unlikely to ever need it, but fun to practice!)

Finally, here’s an example of why you want to dress your knots, use a backup, and avoid cross loading a bowline. (Yes, this is a large diameter rope, and yes, it’s tied too loosely and not dressed, but it's still an interesting demonstration.)