Gwyn Griffiths is a marine technologist. He was Chief Technologist at the UK’s National Oceanography Centre and Professor of Underwater Systems Engineering at the University of Southampton. Over a 40-year career he took part in five oceanographic expeditions to the Polar Regions, experiencing at first hand the tremendous advances in technology – from thermometers to underwater robots. Blending personal recollections with illustrations of engineering and scientific challenges of working around, in, and under ice he will share results that rewrote the textbooks on areas as diverse as marine biology and glaciology.