I lead the halibut over the gaff hook like you would a salmon over a net. Then just lift the hook right up through him and pull him on into the boat in one motion. An extreamly sharp gaff really helps.

To subdue I usually stick 'em in the brain with a short, stout, sharp knife and give a few good twists. Immediatly cut the gills and let 'em bleed out in the self-draining fish box and then transfer them into your cooler/hold full of crushed ice.

Dang! I've got to go catch some halibut.