Ha, just reach down and stick them. Anything up to about 100 lbs usually isn't a big problem for one person.

Here's my drill:

Bring the fish up on the starboard side of the boat so that it's stomach is facing away from the boat. Put the person holding the rod towards the bow while the gaff-man stands toward the stern. When the fish gets about a foot below the surface, use your left hand to grab the leader/line and gently pull the fish up so that it's laying flat about an inch below the water. Use your right hand to slip the gaff into the water between the boat and the fish, tip of gaff should be pointing away from the boat. Aim for a spot about two inches back from the gill line on the shoulder/meaty side of the fish (this is the side facing the boat). Pick your spot, get a low grip on the gaff, and pull up fast with your right hand. Once the point hits the fish, you can let go of the leader and get both hands on the gaff. Lift as high as you can with your arms, then step back/ lean back and you can pivot the gaff on the edge of the boat. This way you never actually lift the full weight of the fish. Lean back, pull back, walk back, whatever until the fish hits the deck. If the gaff's in the right place, the fish usually freezes up fairly well, so don't pull the gaff out until it's in the fishbox or hog-tied.

If I have an empty fish box, I pull them up and drop them in, if there's not much room left, then I shoot(over 70 lbs), hog tie, cleat off to a corner.

Also, there's difference betwen clubbing/shooting them in the head, and clubbing/shooting them in the brain. Brain is an inch or two back from the top eye. You can wail on a fish's head for a long time without slowing it down if you're not hitting the right spot. Don't hammer on it while it lays flat, get your club around the top edge of the fish and try to crush that spot behind the eye. The fish will have a dent there if you do it right.

I'd take a pistol if you're in a skiff, but still wouldn't worry much about a harpoon. Just make sure your shot hits where it needs to.

good luck,
david