I have gaffed Halibut up to 60 pounds, now I use my Harpoon. But it is relatively easy to gaff the smaller 40 and below. What you need is the right gaff, one that has a straight hook on it, not curved as you would use on a Tuna. A trick that I use is to take the gaff (wood) and file down the back side so you can lean it against the gunnel of the boat.

When you hook up, bring the halibut to the surface but don't break the water. With a swift motion, swing down and slightly towards the boat and gaff the halibut in the head. Continue the motion and turn the gaff so the back of the gaff comes to a rest on the gunnel of the boat. The halibut will have a bend in him and the white of his belly will be facing outward. Now have your buddy slit the gills and beat him once or twice or more, if you are into that kind of thing. Then haul him aboard, its amazing how the halibut will calm down when on the side of the boat with the arch in his back (Usually.......always be prepared for the wild and crazy butt.)

Steve Ng