Who created the sat nav?

There's no single inventor of sat nav as we know it today. It's the result of decades of development involving many contributors across multiple fields. However, key players and developments include:

* The US Department of Defense (DoD): The foundational technology, the Global Positioning System (GPS), was developed by the DoD. This provided the crucial satellite network for location data.

* Numerous companies and researchers: Many companies have contributed to the development of the hardware (GPS receivers), software (mapping and route planning algorithms), and user interfaces that make sat nav systems accessible and user-friendly. Specific companies that played a large role are difficult to pinpoint as the technology evolved gradually.

Therefore, it's impossible to credit a single individual or entity with creating sat nav. It's a collaborative effort built upon decades of research and technological advancements.