On the detection screens of other nuclear submarines, two friendly submarines suddenly disappeared.
In an instant, all the submarine pilots tensed up.
"Where did they suddenly go?"
"What happened?!"
"Could it be that a Megalodon has appeared?!"
They talked over each other anxiously.
"But our sonar hasn't detected any trace of a Megalodon! Could it be that the Megalodon can evade sonar detection?"
"That's impossible! Sonar works on the principle of ultrasound echo; any moving creature should be detectable!"
It's important to know that sonar technology is highly advanced today. Under normal circumstances, even noise-free submarines of various types are unable to evade sonar detection.
Not to mention even more noticeable marine creatures — whether they're small fish or large ones — swimming requires body movements that produce noticeable noise.
So sonar easily detects marine life, and many fishermen use sonar equipment to catch sea fish.
