Prusik knot is great. Used it for attaching a tarp over the cockpit of a sailboat for some shade by attaching to the shrouds and stays. Holds extremely well in

Prusik knot is great. Used it for attaching a tarp over the cockpit of a sailboat for some shade by attaching to the shrouds and stays. Holds extremely well in high winds too. Some use it as described by above post to climb the mast.