This is a detailed history of the development of radios in the US Navy up to the end of World War II. Most of the book is about ship-based radios and shore-based radio stations. There are two more chapters on radios for aircraft. There are also chapters on radio direction finders, RADAR, proximity fuses, Sonar and radio-controlled aircraft. The appendices include a good chronology of naval radio history. With 656 pages, this is a very technical study.