Ate limpets once. My dad had a book called "Edible Incredible" and we tried all sorts of food from the sea including limpets (hard to collect and turned the water they were cooked in BRIGHT green), sea cucumber (5 little strips of longitudinal muscle along the inside - helpful little guys clean themselves by throwing up their insides as a defence mechanism) and bull kelp pickles (5 changes of water to deslime them before pickling).
Unusual man, my dad but very cool.