Fish left swimming are a small guarantee of a sea angling future. Presenting the mackerel bait correctly is important. One can fillet the fish, on both sides, using this rather large bait for species such as the cod family, conger eels, tope, bull huss, skate and rays and many others. If only small species are below the boat, try slicing the lash into a number of strips. Try to retain a little of both silver and black stripe on every bait.
Nothing is more maddening that to lose badly presented bait off the hook.
I like to pass the hook two times through the lash. A couple of turns arounf both lash and line, slightly above the hook eye will help to ptrevent this happening.