I live near the sea. I sail and fish and have more than once dropped my keys into the water. I find self inflating keychains, while successful, to be very expensive. Another solution is a cork from a champagne bottle or cork sphere attached to the keys but these are often unattractive. In this Instructable we are going to make use of a knot called a "Monkeys fist". It was used in days of old to store long lengths of surplus rope on ships and rebellious sailors would slip lead weights into the middle of this knot to make a weapon. By using floating rope to tie the knot, a large amount of floating material can be attached to your keys, thats a good thing!