When I started spearfishing I had no knowledge of fish spearing equipment. I bought my first speargun, and when I saw the shaft with floppers it made perfect sense. The fish I was going after didn't require anything more complicated, but later on I learned of slip tips and they looked to me like a major hi-tech advancement in spearfishing gear. At some point I realized that a flopper on a shaft is the modern day equivalent of a simple barb used by ancient spearfishermen. So I made and used this avatar for a while to acknowledge the history.
One day I thought about Inuit hunting seals, I've seen videos of this. Though I've never seen their hunting tools, by the way the hunter was holding on to the rope once the spear was thrust I figured he must have put a slip tip into the seal. I then thought doh! that's probably how whale hunting harpoons are rigged too. So slip tips are a very old invention by human kind, that's been applied to modern spearfishing. It's also interesting to note that if you get a complete pass through with the shaft, and you're using one where the shooting line attachment point is some distance away from the rear end of the shaft, the whole shaft behaves like a slip-tip.
I think the pics from this website http://elfshotgallery.blogspot…-of-toggling-harpoon.html show well the parallel between the old gear and the new.
