Abstract: This invention provides an improved fishing tackle depth planer and release mechanism. Only a strong pull from the fishing rod will cause the mechanism to release, whereas a relatively light tug from the tackle end of the line will trigger the release. The mechanism not only trips the planer out of its diving orientation, but also allows the planer to slide down the fishing line to the lure once a fish has struck. This feature permits the fisherman to use the planer a great distance away from the lure on the fishing line. The release mechanism comprises a plug, a corresponding sleeve and surrounding ring assembly, and holes in each through which the fishing line is threaded. The planer has a hemispherical weight rivetted through it to provide balance without a keeling effect.