https://reefinnovations.com/services/habitats-reef-balls-create-efh-essential-fish-habitats/deep-cover-protective-habitat
Sometimes you want to protect a species from spear fishermen as well as larger predators. The Deep Cover protects fish and excludes fishermen. The large open is under the cover of a concrete lip. At @ 3′ high and 6′ long this will do its job. You could also attach some Reef Balls to the top for additional habitat.
