Low-mid tide, submitted on July 5, 2016, but found in the summer of 2010, but exact date not noted at the time. I have wondered over this conch shell for a long time, and although Dog Conch is the closest I can come up with, I'm not 100% confident in this ID. Since this would, I think, be quite unheard of on the coast of California rather than where it belongs in the info-pacific, I decided it must be a store-bought shell that made it's way into the ocean and stayed there for some time before being washed up with other debris for me to find.