A GPS waypoint is a great way to store a record of a fishing spot and return to it time and again. But for actually fishing a specific reef or hole it cannot compare to a marker buoy. The buoy provides a much more tangible visual reference to where the fish actually are. It's just a little easier to relate to when you are casting or trolling. It requires no conceptualization - transferring an image from a tiny screen to a spot on the water. The buoy is there, visible and can be seen by both people in a canoe or even two canoes working a spot.