Helical Knot

Quite a few cavers believe that the Helical Knot is superior to the Prusik Knot. I find that it is easier to move when properly adjusted, but it takes some experience to determine how tight to make the knot. It appears to be more tolerant of excess slack than the French Prusik. Bob Thrun notes that most of the load is taken by the top of the knot, and recommends tying the knot by winding the free end downward as shown - but he notes that others have reached the opposite conclusion. I never seem to pay much attention to it myself.

The helical elongates more than the Prusik Knot, but not as much as the French Prusik. I've had good luck with it over the years, but I always know that I have the Prusik to fall back on.