The rock art of southern Scandinavia is characterized by depictions of watercraft. The majority are close to the coast, and they have been the primary focus of research. Less attention has been paid to similar representations associated with two large inland lakes in southern Sweden. In this article we present the results of fieldwork around Lake Vänern and Lake Vättern and consider the relationship of this rock art to the better-known images on the coast. We explore the practicalities of navigating between the sea and the interior and suggest that there was an important contrast between an early eastern sphere extending to Lake Vättern from the Baltic and a later western sphere connecting Lake Vänern with the Atlantic.