The fourth-century B.C. (375-350 B.C.) shipwreck at El Sec is located close to the islet of the same name in northwest Palma Bay on the island of Mallorca in Spain's Balearic Islands. Located at a depth of 33 m (108 ft), the wreck was first discovered in the 1940s. It was in the late 1960s when Spanish archaeologist and cartographer Josep Mascaro Pasarius published a study about an assemblage of Attic black-glazed pottery from the wreck, suggesting that this was the first ancient Greek ship found in Spain. The pottery was recovered by amateurs, fueling an interest in nautical archaeology and underwater heritage protection. In 1970, the foundation of the first Balearic institution sponsored the first archaeological mission at El Sec. Navy divers, who had no training in underwater archaeology, worked from the Spanish navy vessel Poseidon for three days with the aid of explosives to recover 530 artifacts without any record-keeping. The explosives were designed to 'recover' anything that was hidden beneath a layer of bronze lebes (cauldrons), which had formed a concreted mound over time. According to Francesca Pallares (1972), those explosions damaged the archaeological remains and also facilitated looting of the site.