(Grapevine Bend, Double Englishman’s Knot) This variation of the ordinary fisherman’s knot is a very secure bend, widely used in climbing and in search and rescue operations. The bend consists of two double overhand (strangle) knots, tied around the opposite standing parts. For joining fishing lines it’s better to tie a triple, or even quadruple fisherman’s knot. All variations of this knot tend to jam under strain, and in situations when the knot needs to be easily untied other bends are preferable.
ABoK #294, #1415
Cross the running ends, putting the left one over the right one, and put the left end behind the right end.
Pass the running end of the left rope over itself, then turn around the second running end and the first standing part from behind.
Thread through the two top loops.
Pass the second running end around the first standing part from beneath and cross it over itself.
Pass around both standing parts from beneath again.
Thread through the two bottom loops.
Tighten the knot.
The double fisherman’s knot is complete.