The fate of Russian officers during the Civil War is still an active field of study. The author has compiled a database of naval officers for prosopographical analysis. This statistical analysis of the biographies after 1917 makes it possible to know precisely what percentage of officers joined which political camp, abstained from participating in the Civil War, emigrated or remained in Soviet Russia, what proportion changed sides, etc. In this way it is possible to take stock of their political commitments in an objective way. Although it represents a step forward compared to the often partial and biased approaches that prevailed in historiography, the prosopographical and statistical study is only of interest if it also allows us to question the motivations of the actors, to detail the factors, ideological or career, that determined their political choices and to evaluate their respective influence. To this end, this article focuses on the naval officers who were registered in Petrograd in 1918, at the time of the dissolution of the former Imperial Navy by decision of the new Bolshevik power.