The second beacon

"Beacon," Zhou Qi said calmly.

"Beacon, standing by," the soldier replied.

The soldiers had set up a signal tower as tall as a person next to the drilling platform. The red and blue lights on the tower flickered alternately, making it look like a light tower used to guide people back to a military base.

But this was no ordinary signal tower. Instead, it was an underwater sonar transmitter, equipped with an HFG-091 electroacoustic converter and signal processor.

The base array, rack server, and auxiliary equipment were all integrated within the signal tower.

At the same time, Zhou Qi would bring along an active sonar device the size of a suitcase when he entered the subterranean river to receive the coordinates of the signal tower.

The efficiency of transmitting electromagnetic waves underwater was very low. Therefore, sonar equipment became the most critical tool when the Qing Consortium was assessing how to transmit information underwater.