The keel is a ship's longitudinal structuring element, and its discovery is always an important moment in the archaeological excavation of a shipwreck. When it was found, after an extensive search, the scantling of the Dauphine's keel proved to be remarkably small scantling, given the overall size of the ship.

Even more than the keel, however, the keelson was the major structural element, and its dimensions are impressive. With a height of 31 to 32 cm and a width of 34 cm, it was the real backbone of the keel.

Archaeological and dendrochronological analyses have shown that the Dauphine's keelson was taken from an older vessel and re-used. Although the presence of sapwood at the outer edge allowed us to date the felling of the tree to 1678, the piece bore traces of having been worked in a way that had nothing to do with the Dauphine's construction. It was made from several pieces joined by a long scarf joint, and was probably taken from a vessel that was being dismantled. Its longest intact section is 15 metres long.