Water bowline the working end around the standing line and back through both half hitches. This is illustrated in the three pictures below. Water bowline The water bowline is a type of knot designed for use in wet conditions where other knots may slip or jam. Although similar in finished appearance to the double bowline, the water bowline is formed with a clove hitch as the loop in the standing part of the rope. This is similar to the double bowline, which puts the running end through a round turn. The additional friction from the clove hitch increases the security of this
Arf invariant of a knot the knot, constructed from a set of curves on a Seifert surface of genus "g" which represent a basis for the first homology of the surface. This means that "V" is a 2"g" × 2"g" matrix with the property that "V" − "V" is a symplectic matrix. The "Arf invariant" of the knot is the residue of Specifically, if formula_3, is a symplectic basis for the intersection form on the Seifert surface, then where formula_5 denotes the positive pushoff of "a". This approach to the Arf invariant is due to Louis Kauffman. We define two knots to be pass equivalent