The Surgeon's Loop is used to create a Loop-to-Loop connection or create a Loop connection that will allow the fly to maintain its action in the water.
Uses: The Surgeon's Loop can be tied quickly and easily in the end of a line. It is often used to make a loop to loop connection or to create a loop which allows the artificial lure or fly to move naturally.
Tying it: It is tied in the same way as the Double Surgeon's Knot.
Advantages: The advantage for this knot is that some sources claim that it retains a high proportion of ideal line strength.
Double Surgeon's Loop