I carry a spearhead/harpoon which has worked very well while fooling around at the beach spearing crabs and flatfish. I wouldn't use my knife for this unless I had a spare (I usually have a few spares) Can you imagine the crappy feeling of thrusting at a fish only to miss and break or lose your knife? I don’t know if I would want to risk such an important piece of gear as my knife in that way. Just MHO though.