Dr Philippe Blondel has written several books about sonar and its applications, backed by experience in all oceans (except the Antarctic). He is the Deputy Director of the Centre for Space, Atmosphere and Oceanic Science (CSAOS), and a Senior Lecturer in the Department of Physics at the University of Bath (UK). He previously worked at the Southampton Oceanography Centre (SOC), and the Institute of Oceanographic Sciences, Deacon Laboratory (IOSDL) in the UK, and the School of Oceanography, University of Washington in the USA. His research group is active in developing new acoustic sensors, designing new processing techniques, and applying them to habitat mapping, marine geology (e.g. cold-water coral reefs and tsunami-generating areas) and the effects of climate change on marine environments.