In the south-west of Scoglio del Catalano, a basaltic platform rises from the bottom and reaches 13m from the surface. It is fragmented in various sections, surrounded by landslides and a Posidonia grassland. The rock is characterized by deep fractures and in various points the collapsed boulders form passages and ravines.
The maximum depth does not go beyond the 22m and there are several routes developing around the various features of the shoal, which is not served by buoy.
The rocks are covered with a thick stratum of brown seaweeds (Cystoseira spp., Padina pavonica, Stypocaulon scoparium and Sargassum vulgare), while the bottom is characterized by a large grassland of Posidonia which, in some stretches, also grows on the rock. During the route, you will meet several passages and ravines dominated by species living in not very illuminated environments with madrepores, bryozoans, and sponges which often house colored nudibranchs. On the detrital bottom it is possible to observe some specimens of pen shell (Pinna rudis), a protected species.
In the areas interested by landslides, it is possible to observe brown groupers and small shoals of brown meagers; everywhere there are salema porgies, wrasses, and mullets, while small groups of common two-banded seabreams wait for some preys. On the seaweed carpet, several sea urchins also graze.