I made my own just to see if it would help. Take any 5 gallon plastic pail, cut off the upper 3-4 inches where the ridges are, save that. I made a tapered nylon sack about 3 feet long that attaches securely around the plastic pail "ring", tapers from full size to about a 6" opening. It goes overboard on the opposite side of the downrigger when I'm alone, keeps the boat running straight and helps in slowing it down. I'm sure you can make the same with something like an Ikea bag. If it works, you have accomplished something on the cheap.