Your choice of crochet edge can make or break your design. Leaving an edge unfinished is not the end of the world, but if you really want your project to soar, choosing an appropriate finishing stitch can really take it over the edge! - Crafting In Line
This hat is what I think of when I see the words "stacked shell stitch, but I don't know if that's what it is. I have a hard time seeing the shells in these patterns. Gives it its own, nice look, for sure.