Not a very usual sight, a large Cook’s turban shell (Cookia sulcata) climbing up brown kelp Ecklonia radiata. As far as I know, they usually crawl on rocks where they graze short algae. Perhaps they can find something tasty on the fronds as well. Often where you can find turban shells, you meet stingrays as well, they love these snails.
I’ve made this picture in Goat Island marine reserve near Leigh. Note the shell is completely encrusted with pinkish coralline algae, however, the shell itself is creamy-pearly-white, suitable as a material for art work.