Plug the scuppers of your Jackson Kayak with these scupper plugs. The old adage, Can't fit a square peg in a round hole doesn't apply here. The round Jackson Kayak Scupper Plug will squeeze together and fit tight through the oval scupper hole on the kayak. Once in it will spread out on the bottom side and form a tight seal. Reverse is true for the Oval Scupper Plug in the Coosa and Cruise 10. These 2 kayaks have a slightly larger and more round scupper hole. It may seem odd, it did to us, but this is how the plugs fit and work.