Portuguese bowline

The Portuguese bowline (Portuguese: Nó volta do calafate), also known as the Bowline on a coil, Caulker's bowline, or Lisbon surprise, is a variant of the bowline with two loops. The two loops are adjustable in size. Rope can be pulled from one loop into the other, even after tightening. Among other applications, the knot can be used as an equalising anchor, a litter bridle or a makeshift Bosun's chair. It is often regarded as one of the more important bowline variations.