How to Tie the Tugboat B (Double Wrap)
Usage
Tie the Tugboat B (Double Wrap) when you want a fixed end loop you can actually get back after it has held a load — something the closely related Perfection Loop is notorious for refusing to do once fused solid. This is a symmetric, double-collar fixed loop: the working end wraps the standing part twice, mirroring each wrap, so the loop closes under two balanced collars instead of one, spreading load evenly through both sides.
It belongs to the Double Dragon family, one twist away from the Perfection Loop but on a different structural base — which is exactly why the two behave differently once loaded.
Why Learn the Tugboat B (Double Wrap)?
It resists jamming at light-to-moderate load better than its lookalikes, and it's easy to confuse with the plain Double Dragon or the Perfection Loop while you're learning. If you want to compare all three side by side, the Knot IQ app keeps the family together in one place.
Common Uses
Camping and Bushcraft
- Fixed end loop for tarp tie-outs and shelter anchor points — dress for symmetry and leave a full tail.
Everyday Utility
- Hauling, hanging, and attaching rope to hooks, rings, or hardware. Expect it to pinch and need effort to release after heavy loading.
Trucker's Hitch (Tied in the Bight)
- Mid-line loop in a trucker's hitch, tied in the bight, as a slip-knot alternative — fine for lighter cinching; a dedicated releasable loop is friendlier for repeated heavy hauls.
Light Marine Rigging
- Temporary end loop for light rigging, light loads only — not a substitute for a spliced eye. The plain Bowline Knot remains the better-tested working default.
Other Names
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Notable Features
- Balanced double collar: two opposing wraps mirror each other, matching the load paths through both eye legs.
- Fixed, centered end loop: loop size is set when you tie it and stays put once dressed and loaded.
- Tiable in the bight: can be formed mid-line without access to either rope end, which is what makes the trucker's-hitch use possible.
- Close family resemblance: looks a lot like the plain Double Dragon but is tied differently — a common source of mix-ups.
Similar Knots
Double Dragon Loop Knot vs. Tugboat B (Double Wrap)
- Advantage: the mirrored double collar spreads load evenly, where the Double Dragon Loop Knot carries a documented asymmetry.
- Disadvantage: the Double Dragon is the better-documented, more widely recognized form of the family.
Angler's Loop (Perfection Loop) vs. Tugboat B (Double Wrap)
- Advantage: resists jamming at light-to-moderate load and unties more readily; the Angler's Loop (Perfection Loop) is known for fusing solid after loading.
- Disadvantage: the Perfection Loop is the more established, lower-profile classic, and simpler to tie if you never plan on releasing it.
Bowline Knot vs. Tugboat B (Double Wrap)
- Advantage: the symmetric collar holds a slack loop's shape well and likely resists slipping in stiff cord better than a plain Bowline Knot.
- Disadvantage: the bowline wins on speed, universal recognition, and easy partner-checking, backed by far more evidence.
Security Level
This isn't a life-safety knot, so the answer here is short. Dressed and set correctly the symmetric double collar reads as stable and has held body weight in hands-on testing, but no strength or security test data exists for this knot or its close relatives, and dressing it for full symmetry takes real care. Fine for camp anchors and everyday utility loops, not for any load whose failure would cost you.
Downsides
- Consumes more rope: the second wrap eats extra length compared with single-wrap loops.
- Demands careful dressing: both wraps must mirror each other for the symmetry to hold up.
- Pinches under heavy load: can seize and take real effort to release after heavy static loading.
- Easily confused with siblings: no test data exists, and it's routinely mistaken for the Double Dragon or the Perfection Loop.
History
The double-wrap Tugboat B was independently tied by Brian Gentry in 2021 as a "Symmetrical Double Dragon," and the International Guild of Knot Tyers matched it back to the community's existing "Tugboat B with double wrap." The wider Tugboat/Flying Bowline name cluster traces to rigger Paul Kruse's knot, and it predates the Ashley Book of Knots, which has no entry for it. The tugboat-crew origin story itself is disputed — knot historian Dan Lehman is skeptical of it, while Kruse defends it firsthand from his own trade.
How to Tie the Tugboat B (Double Wrap)
Step 1
Fold the rope near the working end to make two bights in an "S" shape. The second wrap uses more rope than a single-wrap loop, so give yourself extra working length — a length off the Knot Tying Kit works well for practice.
Step 2
Pass the working end below itself and the standing part, forming the first collar.
Step 3
Wrap the working end around the bight a second time, mirroring the first wrap — the defining feature that separates this knot from the plain, single-wrap Tugboat B.
Step 4
Pass the bottom loop through the top loop.
Step 5
Dress for symmetry so both wraps mirror each other, then set by pulling the standing part and working end.
Step 6
Adjust loop size by pulling the standing part or working end before you finish setting it.
FAQ
Is the Tugboat B (Double Wrap) the same as the Double Dragon?
No — close siblings. The Double Dragon is Tugboat A with a second wrap, tied asymmetrically; this is Tugboat B with a second wrap, tied symmetrically. They start differently and differ in a collar overlap.
Is it stronger than the bowline?
There's no test data for this knot, so that can't be answered either way. People who use it prefer its symmetry and untie-ability, but the bowline ties faster and is far better documented.
What is the difference between a Perfection Loop and a Double Dragon loop?
They look almost identical and sit one twist apart, but they're built on different bases. Untuck each once: the Perfection Loop falls into a slip knot, this family falls into an old harness loop — why the Perfection Loop is known for fusing solid after load while this family levers apart instead.
Important Notes on Safety
No strength or security test data exists for this knot or its close relatives. Do not use it for life-safety or critical loads on the strength of community praise alone.
