There are a number of knots that are frequently used by boaters and are essential for practical purposes. The hitches are knots used for fastening a line to an unmoveable object such as an horizontal rail, a post or a ring such as mooring a small boat or tying of rigging or sails on ships. Hitches are designed to hold when force is put on the rope used to form them. Examples of common hitches used by sailors are a round turn and two half hitches and a clove hitch – ideal for securing fenders. The bends are joining knots and used when needing to join and lengthen or when loops are required for lifting as in slings. The sheet bend is an example commonly used by sailors to join lengths of varying rope sizes. Lops are knots which can be used in similar ways to hitches. The bowline is probably the best known and used loop as the rope can be passed around the object before the knot is tied.