Resumen: During the period of independence, maritime actions were highly relevant for the consolidation of freedom. Even if Chile did not achieve her independence at the “Patria vieja”, the aforementioned country finally succeeded in that process during the government of General O'Higgins. That general sought to create an army able to face enemy expeditions arrived from the peninsula. In this sense, the taking of the “María Isabel” frigate -ancient Russian frigate acquired by Spain to regain their colonies- is a fundamental, but less known episode in Chilean naval history. By means of a qualitative research, we seek to understand the importance to Chilean independence of the “Russian Ships Dilemma” to adequately ponder the Spanish expedition of 1818 towards Chile.