When a skier's tow rope comes untied unexpectedly from the ski boat, a serious accident can result. If you plan to use your boat for water skiing, you must secure the tow rope to the boat with a knot that will turn with the skier without the knot coming undone. The ski rope can be attached to a bridle (a harness tied between the towing eyes on either side of the rear of the boat), or to a ski pole (a vertical, braced pole) mounted on the back deck of the boat. Several common knots work well to secure the tow rope to either attachment point, but only one provides a stable loop.
Make a small loop in the tow rope, about 18 inches from the end (which is called the "bitter end"). Lace about 12 inches of the end of the line through the tow ring. If you are towing the skier with a ski pole rather than a tow ring, don't lace the line through the tow ring. Instead, double 12 inches of the line back on itself.
Grasp the bitter end in one hand and draw it up through the loop. Think of this as if it's a squirrel, sticking its head out of its burrow at the base of a tree (the main part of the line).
Carry the bitter end behind the main part of the line, above the loop, and around the rope. Think of this as the squirrel moving behind and around the tree, looking for nuts.
Push the bitter end back down through the loop. Imagine that the squirrel saw something and dived back into its burrow.
Grasp the bitter end and the side of the loop in one hand, the main part of the rope above the loop in the other, and pull your hands in opposite directions. This draws the bowline knot tight. If you are towing with a ski pole, drop the loop of the bowline over the ski pole.
If your boat doesn't have a pole and you are using a bridle, you can use this knot to secure the ski rope to the pulley/float on the bridle.
For added security, tie the bitter end to the side of the loop by crossing the bitter end over itself, pushing the bitter end through the loop that crossing the end over itself forms, then passing the bitter end through that loop one more time, to form a "double overhand" knot, that will keep the bitter end from slipping out of the bowline.