This may be the most underrated knot. It’s fast to tie under load and applicable all around the boat. It’s much more reliable and certainly easier to untie than its cousin the clove hitch. This knot is secure, does not allow the line to chafe, and is easily undone. Use this hitch to tie a dockline to a mooring.
This video shows you step-by-step how to tie a round turn & two half hitches knot.