Hi all,
I asked Dan why his current speargun models don't have shark spikes anymore and he explained that it can be dangerous, if you are handling a strong fish by the shooting line and the fish darts off, the line may slip through your hands and the gun can stab you from behind (Dan, correct me if I warp your explanation).
I like the idea of a shark point for hunting in shark territory but he does have a point. I was wondering how hard it would be to make a retractable one, I was thinking a bit like those one shot rifle loaders or a sliding bolt lock. If you have space in the front part of your tube and you make cap with a hole the diameter of the spike and you attache a spring to the inner par of the cap in such a way that the spike runs through it (like a ball point pen works, the kind you click the back of to open/close). The spike would have a bar attached to it at 90° and the side of the gun is milled to allow you to move it back and forth. Close to the front it would be milled down with an angle so you can lock it into position. The barrel would need to be reinforced so that it doesn't warp from the strain of the bands. Here is a crappy drawing to illustrate:
I guess there needs to be a lot of reinforcing to do, maybe it could be done as an attachment below the barrel so you don't have to mill the barrel, a bit like some people attach a flashlight: .
Or something like that. Any ideas?