This weekend I was allowed by the boss (wife) to spend few hours working on the design of a hat or two.
My sea urchin grabbed it, but since the bottom of the hats are not a full arched shape, it does not fit perfectly.
The cowboy hat has quite a large area in comparison to the small contact area for the sea urchin to hold on to it. With the water flow and rocks, the hat will come loose after awhile. If you fit the entire sea urchin in the hat and its brim will be way too big to be carried around. I will make some changes and test them before I will make them available.