Skandalopetra diving dates from ancient Greece, when it was used by sponge fishermen and has been re-discovered in recent years as a freediving discipline. It consists of a variable ballast dive using a skandalopetra tied to a rope. A companion on a boat recovers the diver pulling the rope after the descent, always watching over from the surface.
A skandalopetra dive better known to contemporary divers is perhaps that of Georgios Kaggis, a Greek sponge fisherman who, on 14 July 1913, in the Karpathos port recovered the lost anchor of the Queen Margaret, a ship of the Italian Navy, at the depth of 83 m. The skandalopetra (or simply petra, "stone") is a stone, usually of marble or granite, weighing between 8 and 14 kg, with rounded corners and hydrodynamic shape.
It was the only tool used by divers, since the time of Alexander the Great. The fishermen, naked, were secured to the stone with a thin cord. The skandalopetra itself was secured to the boat with the same rope. This link allowed fishermen to dive safely for centuries.
In recent times skandalopetra diving has been newly proposed by some fans as a form of sport diving in apnea, then developing an athletic activity. In modern competitions with skandalopetra, divers are allowed the use of a noseclip, it is not permitted to use other equipment such as a wetsuit, mask or fins.
In this discipline there is no waste of energy and activity is comparable to the descent in variable ballast diving. The athlete, still on the boat, prepares before diving, holding the stone, then dives, remaining motionless and as vertical as possible. After the dive, moves his feet onto the petra and lets himself being pulled to the surface by his companion. It is therefore essential to the synergy within the team diver-assistant, the latter at any time should know the depth to which you will find the divers, feel when they slow down to equalize, leaving the stone when it arrives at the bottom and finally when it is the right time to sail. The divers during the descent handle the stone in different ways serving as brake, as the helm and, of course, as ballast.