Page 66 - Cliff Jacobson - Outdoor Knots

Figure 35. Surgeon’s Knot

Simply a square knot with an extra turn on the bottom and perhaps an additional
turn on top (there are two forms of the knot as illustrated). The surgeon’s knot is
much more secure in slippery materials than the traditional square knot.
Whitewater kayakers use a slippery surgeon’s knot (with quick-release loop) to
tie the slick nylon waist ties of their life jackets.