In a 1957 interview, André Breton reflected upon the aims of Surrealism, the literary and artistic movement he had helmed since 1924: “Que peut-il demander de plus que d’être cette bouée phosphorescente dans le naufrage?” (What more can it ask to be than a phosphorescent buoy in the shipwreck?) This paper explores two interrelated, recurrent tropes of the diver and shipwreck, as they constitute an aquatic current within Surrealist art and literature of the interwar period. From his early texts on automatism and dream in the 1920s to his materialist analyses of the relationship between aesthetics and politics in the mid-1930s, Breton likened the Surrealist exploration of the unconscious to a form of oceanic exploration, “adjusting the compass to South” and descending to an “underwater command post.” Maritime themes also found sustained expression throughout Surrealist visuality of the period, from Robert Desnos’ automatic drawings to Bill Brandt’s photographs of decrepit ship figureheads, published in the journal Minotaure in 1935. Such imagery corresponded to – and owed much to – remarkable advances in undersea filmic technology during and immediately following the First World War. As such, Breton’s diver-shipwreck configuration linked the Surrealist exploration of the depths of the mind to the material conditions of the historical moment.