Vladimir Arnold was one of the great mathematical scientists of our time. He is famous for both the breadth and the depth of his work. At the same time he is one of the most prolific and outstanding mathematical authors. This second volume of his Collected Works focuses on hydrodynamics, bifurcation theory, and algebraic geometry. "Volume II focuses on hydrodynamics, bifurcation theory and algebraic geometry. ? Arnold was a very prolific writer. The publication of his collected works is a huge task and a great service to the mathematical community particularly since his papers appeared in various journals some of which are not easily accessible. ? I have no doubt that these volumes will be of great benefit to the current and future generations of researchers and graduate students." (Gerard Misiolek, zbMATH 1354.01038, 2017)