Adventist Youth Honors Answer Book/Knot/Fisherman's bend
Use: The Fisherman's knot is a specialized bend. It consists of two overhand knots wrapped around each other. It works well for joining thin, stiff, or slippery lines. It requires little dexterity to tie, so is often used in stubborn materials. When tightened, it becomes fairly compact, and the free ends can be cropped very close to the knot. These qualities make it very useful for fishing line--it is less likely to jam a fishing rod than many other bends, and is easier to tie with cold, wet hands.
How to tie:
To tie the fisherman's knot, lay the two ends to be tied alongside each other and facing opposite ways. Tie an overhand knot on the first rope and pass the second rope through the loop formed. Tighten the overhand knot, to prevent the line inside it from flopping around. Then tie another overhand knot on the second rope with the first rope passing through it.