Amongst most of the California spearfishing community Leopard and Horn sharks are a big

. Most simply do not hunt them. There are other more tasty and challenging fish to hunt. A 5-6 ft leopard shark is an extremely powerful animal. And if you do shoot one... expect the likely possibility of damaged or lost gear.
In addition, there are also Soupfin sharks here in our California kelp beds. They get rather largish (6+ft). I have heard stories of them becoming aggressive against divers. A couple of divers shot one at Catalina Island last year I believe. They got it on video. It took two shots to subdue the shark. And both were to the head. The shark was in the 80lb range if I remember correctly. And they are supposed to be decent eating. Although no one specifically targets these either.