Archival research began in 1996, based on a initial corpus of basic data compiled by Gérard Bousquet and Emmanuel Feige. It continued throughout the project, helping to slowly tighten the net in the search for ships that corresponded to the images that archaeological research had drawn up. Initially, it was thought the successive loss of two frigates less than a half-league from the walls of Saint-Malo would not have gone unnoticed, and that they had given rise to a number of reports. Although the instinct was a good one, a number of years were needed before research efforts paid off.
The ships sought in the archives needed to meet a certain number of criteria, which included tonnage and firepower. In addition, they had to have foundered between 1702 and 1705 for the first ship, and between 1748 and the early 1750s for the second.
The archives centre for the département of Ille-et-Vilaine, where the registries for the port of the Saint-Malo admiralty had been deposited, including the minutes of the Clerk's Office and the reports submitted by privateering captains, was a focal point of the investigations. It finally yielded the names of two frigates that sank off Saint-Malo. Other crucial information was gathered during this research, particularly in the archival collections of the Naval Historical Centres in Brest and Cherbourg, the Le Havre Municipal Archives and the National Archives. Incidentally, it is still ongoing.