Abstract: An enhanced sight marker apparatus for slingshots, bows, and other projectile launching devices includes a support block with a trough for mounting and retaining an elongated, fluorescent optical fiber. The trough is deep enough to receive a substantial portion of the fluorescent optical fiber for support while leaving some portion of the peripheral surface of the optical fiber unshielded by the support block for exposure to ambient electromagnetic radiation, and the support block also leaves at least one end of the fluorescent optical fiber exposed and visible so that light transmitted in the core of the optical can be propagated from the exposed end to a user's eye.