In 2002 Promare and CNANS (Centro Nacional de Arqueologia Náutica E Subaquática) conducted a collaborative underwater archaeological survey of a selected segment of the Portuguese coastline near Ericeira, based on historical documents pointing to ship losses in this area, as well as on reports of scattered artifacts. Considering the range of the side-scan sonar available for the survey, the harbor regulations in Ericeira, which only allow boats to leave and arrive at a strict schedule, and the size of our team, we concentrated on a relatively small area to test our hypothesis of where a number of historically known shipwrecks might be found.

One of the best known historical accounts from the seventeenth century, by João Mascarenhas, depicts the voyage and demise of a ship named Nossa Senhora de Conceição. Built in India, the ship was loaded with a precious cargo of pepper, and other merchandise. Valuable gifts intended for the King of Portugal from the King of Persia were also on board. But most importantly, the ship was full of merchants, including Mascarenhas, who were returning to Lisbon having invested their earnings in diamonds. Conceição left Goa on March 1, 1621, and after a journey of about nine months, reached the Azores. Upon leaving Terceira, Mascarenhas reports that the ship was attacked by seventeen North African pirate ships armed with 30-40 cannons a piece. After a few days of battling its attackers in the open sea, Conceição managed to sink two of the pirate ships, but was unable to escape. She was set on fire, and foundered with most of her cargo. Surviving passengers and crew were captured by the pirates. While Mascarenhas’ memoir concentrates on his period of slavery in Algiers, it also provides very valuable information about the events that led to the capture of the ship, and consequently offers clues as to the possible location of the shipwreck. Dating to an important period in the development of ship construction technologies, this vessel, along with the two pirate ships that sank in its vicinity, would be a very valuable archaeological find.

Our survey, unfortunately, did not locate these sites. However, following the historical accounts, while assessing navigation parameters in this area based on the estimated capabilities of seventeenth century ships, was a valuable practice. Our survey benefited us in terms of understanding the routes followed by the Portuguese Indiamen in this era, and acquiring experience in working in the difficult conditions of the North Atlantic.

Esclave à Alger, Récit de captivité de João Mascarenhas (1621-1626). Paris 1993 (Chandeigne).