[alanw]

Originally Posted by Dave Legacy

Unless it says in the literature that you may use a harpoon to land California Halibut, or a harpoon may be used on legal sized finfish in general, I wouldn't make the assumption that it is legal to do so.

Dave is right on. I'm not an expert but the regs seem very clear to me on harpoons.
28.65. GENERAL. Except as provided in this article, fin fish may be taken only on hook and line or by hand.

So unless you find an exception like the one for sharks skates and rays, or the new for 2015 exception for Pacific Halibut, I wouldn't use anything resembling a spear or harpoon to take your catch.

It looks like you can use a bow and arrow (or crossbow) fishing setup though