Dr. Vasudev K. Aatre reached the highest position in the Defence Research and Development Organisation due to his outstanding contributions in many spheres of defence technologies. Hailing from a family of great traditions and values, he was brought up in an atmosphere conducive to his holistic development. He had a brilliant academic record and a meritorious career in India and abroad. He had the opportunity to conduct his research in prestigious institutes such as the Indian Institute of Sciences (IISc), Bangalore, as well as the Technical University of Nova Scotia in Halifax, Canada. He made outstanding R&D contributions in his capacity as Scientific Advisor to Raksha Mantri for five years. During this period, he gave new impetus to R&D programmes of national importance such as development of Light Combat Aircraft (TEJAS), Kaveri Engine for LCA, Electronic Warfare, Main Battle Tank (MBT) Arjun and Missiles. The Sagardhwani is an appropriate tribute to a great scientist of India, Dr. Vasudev K. Aatre who has set the DHWANI, a keynote for research in the field of Under Water System SONARS and Torpedoes in the country. He was instrumental in the development of the oceanographic ship “Sagardhwani” for oceanographic research. Dr. Aatre has a unique personality, which is easy to admire and difficult to emulate. A man of powerful expressions and oratory skills, he was able to convince the political leadership, bureaucrats and scientific community to achieve the high goals he had set for himself and the DRDO during his tenure as head of DRDO. A compilation of his brief biography and impressions of his colleagues and friends, who have closely interacted with him for several years, this book is a humble tribute to this great scientist. This biographical sketch will serve as a role model for young scientists as well as other young students who are inspired to serve the country.