Abstract: The invention takes the form of a hydrodynamic plane which carries a fishing line up and down along a weighted downrigger trolling line. The position of the plane is controlled by the fisherman through the fishing line which is releasably clipped to a leader attached to the trailing edge of the plane. Whenever there is a mild amount of tension on the fishing line the plane is held in a down-planing position so that the device will dive and be held against the downrigger weight by the hydrodynamic force. The weight of the plane is balanced so that when the tension on the fishing line is relieved or if the fishing line is released from the friction clip, the plane will automatically pivot to an up-planing position and rise to the surface. Thus, the plane will automatically rise to the surface when a fish strikes the hook, or the fisherman can make the device rise to the surface on command without releasing the fishing line so that he or she can check the bait or the lure and send the device back down again.