Longer period in submerged condition has been an important objective of submarines since early days and the propulsion has played a key role. The book catalogs evolution of submarine propulsion and has insights to development of nuclear propulsion by US, USSR, UK, France, China, India, Brazil and Argentina. The Indian experience of developing a land based nuclear propulsion prototype and its nuclear submarine INS Arihant has been described. Experts from France, Brazil and Argentina have contributed chapters on the projects from their respective countries. Forewords by Sekhar Basu, Chairman Atomic Energy Commission & Secretary Department of Atomic Energy ; K N Vyas, Director Bhabha Atomic Research Centre Anil Anand was the Director, Reactor Projects Group, leading the Programme for Nuclear Propulsion for the Indian Nuclear Submarine Programme.