If I keep up this hobby, I will never need to buy another pocket knife. I carry the CRKT regularly.
For a bathing beach, I find a lot of munitions. Mostly shotgun shells, but the thing that looks like a tip to an artillery shell is, well, the tip to an artillery shell (or a rocket). The round ring is a piece of another one. The tail fin is from a parachute flare. And yes, that is a link from a machine gun.
I won't need to buy lures anymore, either. There are several areas of the lake guys go to just to search for lures...