In this interview, Klaus Hasselmann discusses topics such as: his family background and how he became interested in physics; getting his PhD from the Max Planck Institute for Fluid Dynamics and Gottingen University; Walter Tollmien; University of California, San Diego Institute for Geophysics and Planetary Physics; Scripps Institute of Oceanography; Walter Munk; Norman Barber; John Miles; Hugh Bradner; George Backus; Klaus Wyrtki; Carl Eckart; Charles David Keeling; researching storms in the south pacific including Hawaii; Frank Snodgrass; Gordon Groves; measuring waves in the North Sea; be