Nonsense. There were decades of commercial transatlantic flights before the widespread adoption of GPS. No one painted giant arrows on the ocean. Airliners navi

Nonsense. There were decades of commercial transatlantic flights before the widespread adoption of GPS. No one painted giant arrows on the ocean. Airliners navigated using a mix of dead reckoning, ground signals, and sometimes even celestial observations. https://www.smithsonianmag.com/air-space-magazine/707-flight-changed-everything-180971219/ https://www.smithsonianmag.com/air-space-magazine/707-flight... GPS (and other GNSS) make civil aviation slightly safer and more efficient but it's hardly necessary for routine flight operations.