Ive used that PMI cord from REI to hang my hammock extensively. It works quite well and when wet doesn't stretch significantly (Ive never had to re-pitch anything because of stretch) the only down side is when it gets wet knots that normally wouldn't seize (like the alpine butterfly) start to seize. also be careful you don't cut into the bark of any trees, plastic tubing slipped over the line works great for this.