S C M O - Offshore Knot

This knot is used to attach swivels or snaps to a double-line leader.

Slip loop end of double-line leader through eye of swivel. Rotate loop end a half-turn to put a single twist between loop and swivel eye.
Pass the loop with the twist over the swivel. Hold end of the loop, plus both legs of the double-line leader with one hand. Let swivel slide to other end of double loops now formed.
Still holding loop and lines with one hand, use other to rotate swivel through center of both loops, at least six times.
Continue holding both legs of double-line leader tightly but release end of loop. Pull on swivel and loops will begin to gather.
To draw knot tight, grip swivel with pliers and puch loops toward eye with fingers, while still keeping standing lines of the leader pulled tight.