The primary objective of the NWO-sponsored AQUA program is to gain a better understanding of the effect of water quality on multiphase flow dynamics, in particular on cavitation and air lubrication for drag reduction. The participating universities and research institutes include Delft University of Technology, University of Twente (Physics of Fluids group), and Royal Netherlands Institute for Sea Research. At Delft University, we currently have 2 open PhD positions related to cavitation research.