Deception has long been a central component of Russian warfare, a fact that has become evident in modern conflicts where the state has been involved, not least during the annexation of Crimea in 2014. After the armed conflict, an unstable period unfolded in several Ukrainian regions, as well as in the adjacent maritime areas of the Black Sea and the Sea of Azov. Russia’s aggressive behavior in the sea regions was driven by a goal of dominance, manifested through multifaceted actions that included both conventional and unconventional methods. A gray zone conflict was launched in the maritime domains. Existing research studying Russia’s naval warfare has paid only limited attention to use of deception, which means it misses a key aspect of its on-sea activity. With the aim to contribute more broadly to research on Russian naval warfare, this study has used a theory of deception to describe how and when the state has employed methods related to the phenomenon in the gray zone conflict. The result of the analysis shows that Russia, in its multidimensional conduct across the broad spectrum between war and peace, has utilized deception methods in various instances, with an increased intensity in the year preceding to the conflict’s escalation into full-scale war.