'out of no where'? Really? Well, I do not expect you to know about Dr Paulraj and his contribution to the development of APSOH (Advanced Panoramic Sonar Hull-mounted), HUMVAD (Hull Mounted and Variable Depth), HUMSA (Hull mounted Sonar Advanced). Contrary to what you think, Indian sonar is pretty good - at least navy is not complaining. In fact, most of recent IN ships use Indian made sonars rather than imported ones.
The Indigenous Panoramic Sonar
The Indian Scenario
NPOL hands over next generation Sonar design for India Navy Ships | Frontier India Strategic and Defence - News, Analysis, Opinion - Aviation, Military, Commodity, Energy, Transportation, Conflict, Environment, Intelligence, Internal Security
Nuclear Power in India
The Hindu : Front Page : PWR building shows indigenous capability, says Kakodkar