The Round Turn and Two Half Hitches it often referred to as a useful boating knot. A Round Turn and Two (or more) Half Hitches is commonly used for attaching a boat mooring line to a dock post or ring. However, this is probably less secure than the Anchor (Fisherman’s) Hitch.
The many uses for this not include: to attach a swing rope to a tree branch or frame; to attach the painter of a small craft to a mooring ring or rail, and to attach a tow rope to a vehicle. For added security, tape foresees the working end to the standing part after the knot has been drawn up tight.
ABoK 1720. The Round Turn and Two Half Hitches is named by Steel in 1794. If a spar is small a round turn is preferable to a single turn. It makes a stronger knot and dissipates the wear. 1721. Two Round Turns and Two Half Hitches, so called by Dana in 1841, and by subsequent authors, was originally called Rolling Hitch (Falconer, 1769). It is a strong, old-fashioned knot that is excellent to tie to the limb of a tree.