The sea of Santa Marinella is characterized by a unique clarity which over the years has protected the seabed rich in a particular Mediterranean flora and fauna especially in the Pierucci Wall which is almost a km long. Here you can find rocks and coves where many species of fish have their dens while in Punta della Vipera you can see the ruins of an ancient complex of tanks for fish farming with a large murenaio. The complex is among the largest in the Mediterranean and is made up of a set of communicating rectangular pools around a circular central pond.
It is a paradise for diving photographers who can also enjoy the remains of wrecks such as that of Liburna, at 38 meters deep, a cable laying ship sunk about thirty years ago to prevent trawling that ruins the seabed.
Given the shallow depth of the sea, diving can also be done in apnea (holding the breath). While for those wishing to learn, in Santa Marinella there is also a centre with a school for divers.