Every year we try to go camping for a few days on the farm where my father-in-law grew up. There's been a rope with a piece of wood as a swing hanging there for years that the kids use to jump into the middle of the creek. My husband wanted to change the rope this year. We used 25' of natural 3/4" fiber rope. After we cut down the old rope we secured the new one with a bowstring knot at the top so that (hopefully) the loop will expand with the growth of the limb it is secured to.
My nephew was the first to try it out.At the end I made what is called a monkey fist. They are supposed to be made with smaller line and I wasn't sure we could make one 3/4" thick rope. I think it turned out well and we all hope it will be there for many years of fun.