Hans van Haren is a Senior Scientist of Physical Oceanography at the Royal Netherlands Institute for Sea Research (NIOZ) at the island of Texel. During the past three decades, he has led many international research cruises investigating the dynamical effects of density variations in the ocean, ranging from diapycnal mixing to internal waves. He has also studied the impact of breaking internal waves on sediment transport and ocean biology. The focus is on observational studies, including interest in the development of instrumentation such as high-resolution temperature sensors. Bycatches of his physical oceanographic research include deep-ocean lunar periodicity of zooplankton motions, human body sensitivity to temperature variations (induced by internal waves near a beach), and establishment of the deepest point on Earth. Educated in Experimental Physics and Physical Oceanography at the University of Utrecht, he has held several visiting positions in Canada, Japan, France and Australia. He has published more than 120 first-authored refereed papers and has been a frequent convener of oceanographic sessions at the European Geophysical Union and other international conferences. In addition, he has held a number of positions in relation to editorial work and has sat on various editorial boards of scientific journals. Hans is currently President of the International Association for the Physical Sciences of the Oceans (IAPSO).