Sheet Bend Rope Extension
Notes and Resources:
This method of rope extension allows you to join a new rope anywhere along an old rope; it does not depend on end knots to stay put. It lays flat against the body, and can be easily adjusted after tying by sliding a bit of slack through the knot in order to fine-tune its positioning (for example, so that it doesn't wind up right on a collarbone).
It takes a little practice to get the hang of this method, but once you learn the motion it can be done very fast. I use this almost 100% of the time for extending ropes.
Note that it's very hard to tie this if the rope you're extending is slack; try to situate yourself so that you can keep tension on the old line while adding the new one. Sometimes I move my body away from my bottom while tying, to accomplish this, if I'm extending a rope that is still more than a couple inches long.
A bend is the name for a knot that joins two ropes, and a Sheet Bend is one of the most popular. This slight variation doesn't have a standard name, but could be called a Sheet Bend on a Bight.