We report the archaeological survey, dendrochronological analysis, and archival research concerning two shipwrecks located in shallow waters outside Vaxholm in the Stockholm Archipelago, Baltic Sea. According to oral tradition, the two wrecks are the remains of Neptunus and To Løver, two former Danish warships that were taken as prizes at the battle of Fehmarn in 1644. The Swedish navy then used the two ships until 1659, when they were reportedly scuttled as a blockage along the sea route towards Stockholm. Before being intentionally scuttled, the two ships drifted away and sank. The work presented in this article confirms the substance of the tradition and reports that substantial portions of the two ships are preserved. Moreover, the two wrecks shed light on the scuttling process and the construction of an underwater barrier.