Water Knot
Also known as: Ring Bend, Tape Knot
bend knot
Life-safety notice
TyingPoint's illustrations are for learning. For any life-safety use — climbing, rope access, rescue, or load-bearing rigging — seek qualified in-person instruction, and always inspect and test every knot before you trust your weight (or anyone else's) to it.
Flat webbing behaves differently from round rope under a knot's bend, and most rope bends simply don't seat properly in it - which is why the water knot exists as webbing's own dedicated joining knot, built from an overhand knot that a second strip of webbing is threaded through, following the first strip's path exactly in reverse. Climbers use it constantly to build webbing slings and anchors, since it's the standard way to close a length of tubular or flat webbing into a loop.
What makes the water knot a genuinely different animal from something like the double fisherman's is a well-documented failure mode: it creeps. Repeated loading and flexing - exactly what a webbing sling experiences in ordinary use - can very slowly work the knot looser over time, a behaviour that's been directly implicated in real sling failures when the knot wasn't checked and re-dressed. This isn't a rare edge case; it's routine, expected behaviour with this specific knot, and it's precisely why climbing safety training universally teaches inspecting and re-tightening a water knot before every session, not just once at the time it was tied.
Long tails are the other non-negotiable detail. Because the knot can creep, a short tail can be pulled entirely through the knot over enough cycles, leaving nothing at all - keeping several centimeters of tail on each side gives a visible, physical margin before that becomes a real risk.
Manufacturers of pre-sewn webbing slings exist largely because of this exact creep risk: a factory-stitched sling has no knot at all to loosen over time, which is why many climbers now prefer buying pre-sewn slings for critical anchor components and reserve the hand-tied water knot for improvised or replaceable webbing rather than a sling meant to stay in service indefinitely.
How to tie the Water Knot
Tie a loose overhand knot near the end of one piece of webbing.
Strength & security
Approx. strength retained: 60-70% (webbing)
Specifically designed for flat webbing where round-rope bends don't seat properly, joining two pieces or closing a loop of webbing into a sling.
Cautions: This knot is documented to slowly creep and loosen under repeated flexing and loading cycles, which is exactly why climbers are trained to inspect and re-dress it before every single use, and to keep noticeably long tails so any creep doesn't run the knot out entirely.
Alternatives
- Double Fisherman's Knot
The equivalent trusted bend for round cord/rope rather than flat webbing - not a direct substitute, since neither knot seats correctly in the other's material.
FAQ
Why does the water knot need to be re-checked before every use?
It's specifically known to slowly creep and loosen with repeated loading and flexing, unlike a rope bend such as the double fisherman's knot - regular re-dressing is standard, expected practice, not excess caution.
Can the water knot be used on rope instead of webbing?
It's built specifically for flat webbing; round rope is better joined with a bend like the double fisherman's knot, which seats correctly in round cordage.
Why do some climbers prefer pre-sewn slings over a water knot?
A factory-stitched sling has no knot to creep or loosen over time, unlike a hand-tied water knot, which is why pre-sewn slings are often preferred for critical, long-term anchor components.
How much tail length is considered safe on a water knot?
Most climbing safety guidance recommends at least 7-10cm of tail on each side, sometimes backed up with an additional overhand knot in the tails themselves for extra insurance against creep - the exact figure varies slightly between organizations, but the underlying principle, generous margin against slow slippage, is universal.
Can the water knot be tied in rope instead of webbing in an emergency?
It can technically be tied in round rope, but it doesn't seat as securely there as in flat webbing, and a proper rope bend like the double fisherman's knot should be used instead whenever round cordage, not webbing, is what's actually being joined.
Why is the water knot also called a ring bend?
Because its most common use is closing a single length of webbing into a closed ring or loop for a sling, rather than joining two separate pieces end to end - both uses rely on the identical knot.