There was a time when I was a kid at Cholla bay, that during the biggest tidal movement of the year, (it was summer, 58 or so) the shellfish came out of the sand and started crawling around, and not just one kind either. There were Conch's, thousands of them, along with a lot of what's commonly called Olive shells, and a bunch of other snails as well. My folks and the others who chased the tide that day seemed to know that was going to happen (I've never seen it since) because they had gunny sacks and such to haul the Conch's back in. They had some idea of inlaying a fireplace with them, or some such. I remember very well how much work it was to boil and clean out the Conch's. These were not the big Conch's we used to get diving off the rocks, but one's that were about 4 or 5 inches long. The big one's we just hung by there foot until they just wore out, and then the shell just dropped off with very little of the animal left inside to clean, but man, was it ugly!