Thanks to an agreement signed in 2002 with the Saint-Malo hospital, objects encrusted in ferrous gangue were x-rayed on a regular basis during each archaeological campaign. Working with the archaeologist Olivia Hulot, the team from the Radiology Department of the Centre Hospitalier de Saint-Malo offered its equipment and know-how available free of charge.
These x-ray images allowed researches to both document the objects, and also to sort them based on the interest of each item. Thus, some concretions could be returned to the ocean, while others were stored in water while waiting to be transferred to specialised labs for treatment or casting. On any number of occasions, the team made silicon or resin casts of simple objects frequently found on site, such as nails, architectural pegs and rings. These moulded objects were chosen based on their potential to provide information, and the casts, made by team members during the excavation, were very interesting from a cost-saving point of view.