I purchased a 600' reel of Samson braided polypropylene line, and keep it flaked in an Ikea "Frakta" bag, which is dirt cheap on Amazon (2 for $7). It worked perfectly last summer, and is easily stored in the cockpit lazarette. I was not interested in the bag system seen on Youtube, for a few reasons. It only holds 300' of line, which doesn't seem adequate to me. It is a bit too clever and complicated. (After pulling in the line, you would have to take it apart and reflake the two sections separately. I just flake it directly back into the bag and am done with it.) Finally, if I remember correctly, it was way expensive. The Ikea bag is next to free.
The simple "flaked in a bag" stern-tie can be deployed and recovered just as fast as a reel, is light, and takes up no room at all when not in use. And if you come from sailing, flaking the line gives you a warm and fuzzy feeling.
