During 2009, Arqueonautas Worldwide (AWW) was approached by Barra Sul, a NGO from Santa Catarina in Brazil that had found in January of that year, a wreck site south in Santa Catarina bay. Barra Sul had a survey license issued by the Brazilian Navy and needed archaeological expertise to identify the wreck.

In January 2010, a small expedition team from AWW joined some of the Barra Sul divers and a reconnaissance survey was conducted at the wreck site area. An anchor, a large bronze cannon with a Spanish shield dated 1565, a stone slab with inscriptions, a stone with the Spanish coat of arms, a large pile of ballast stones and cannon balls were visible and were marked on a site sketch plan. Observations at the site, suggested that the wreck was a large late 15th century or early 16th century ship, most probably Spanish.

The data gathered during the reconnaissance mission was analysed together with a list of documented ships lost in the area and one prime candidate apparently ticked all the boxes. The San Esteban, part of an important Spanish fleet on the way to the Magellan Strait, was lost on the 10th of January 1583 soon after leaving Santa Catarina bay. As the “nao provedora” (provider ship) of the fleet, she carried construction materials to build two fortresses and provide defence capability to that remote area of the Spanish territories in the New World. That explained the stone slabs with the inscriptions and the Spanish coat of arms that were found at the wreck site and proved to be the information that convinced AWW’s team that the wreck they had visited was the San Esteban from 1583 and, as such, the oldest shipwreck ever found in Brazilian territorial waters.