Two monkeyfist knots I tied with an old buoy line
The monkeyfist knot is tied from a single line and adds weight so that the line may be thrown more easily between a boat and the dock.
A line with a monkeyfist is often attached to a much larger and heavier tie line and is thrown first by a deckhand or dockworker so that the heavier tie line may then be pulled through the water and ashore or aboard.
Additional weight may be added to the monkeyfist by tightening the knot around a small sandbag or ball or rock. But too much weight will weaponize the monkeyfist, transforming it into a dangerous missile when hurled.