Abstract: A release device for installing between the end of a fishing line and fish hook for freeing a snagged fish hook, the device including a normally closed elongated helical tension spring having a weight attached to the line end of the spring. The device is activated by pulling on the line to stress and elongate the spring which moves the attached weight. A sudden release of the taut line permits a rapid return of the spring to its closed position at which time the kinetic energy of the weight coming to an abrupt halt at the end of the closed spring is transferred into a shock wave passing through the spring and is transmitted to the snagged fish hook to drive the fish hook from its snagged position.