This paper provides a new submarine experiment and shows the results of an interval SLAM (Simultaneous Localization And Mapping) method. The SLAM problem is cast into a constraint satisfaction problem where interval propagation algorithms are particularly efficient. The resulting method is applied to the localization of a submarine robot from the GESMA (Groupe d'Etudes Sous-Marines de l'Atlantique), the Daurade during an experiment in the Douarnenez bay, in Brittany (France).