The Surprising Dangers of Hearing Active Submarine Sonar Underwater

We often marvel at the incredible technology of sonar, but what happens when humans unexpectedly encounter its effects? Sonar, short for Sound Navigation and Ranging, is like the superhero of underwater exploration. It's the tool that search crews used to locate the ill-fated Titan sub, researchers employed to unveil a 30-foot-long mystery beneath Loch Ness, and the instrument sought by the team on the trail of Amelia Earhart and her vanished plane.

Many assume sonar is harmless, almost imperceptible to us humans, even if we accidentally find ourselves in its path. However, the reality is more startling.

How Sonar Works

Active sonar transducers emit pulses of sound into the water, hoping to detect any objects of interest. When these sound waves encounter an object, they bounce back, creating an 'echo' that the system interprets to calculate the signal's strength and provide operators with an idea of what lies ahead.

On the other hand, passive sonar involves listening for sounds made by vessels, which may explain why we often feel a false sense of security around this technology. Sound, unlike light, travels effectively underwater, aiding ships in navigating and 'seeing' beneath the waves.

The Risks Unveiled

Most boats today are equipped with active sonar technology, albeit not as powerful as that of massive navy ships. Australian divers experienced this firsthand last November when a Chinese vessel unleashed its sonar pulses while they were diving.

Richard Marles, Australia's defense minister, recounted an incident where the HMAS Toowoomba encountered trouble with fishing nets in international waters. Divers were dispatched to assist, but a Chinese PLA-N destroyer (DDG-139) operating nearby posed a new threat. Despite warnings of the ongoing operation, the destroyer's sonar, operating at close range, endangered the Australian divers.

Marles explained, "The divers sustained minor injuries, likely due to being subjected to the sonar pulses from the Chinese destroyer."

The Hidden Dangers

The effects of high-intensity active sonar can be startling. Symptoms range from dizziness, disorientation, and temporary memory loss to concentration problems and even temporary hearing impairment. In severe cases, it can lead to organ damage.

According to marine bioacoustics experts, active sonar pulses can be so powerful that they risk rupturing lungs, with pulses exceeding 210dB potentially causing fatal brain hemorrhages.

Imagine hearing a piercing mid-to-high pitch sound underwater, a clear sign that you might be in serious danger if active sonar is at play.

Stay Safe

So, if your peaceful swim suddenly turns into a ringing in your ears, it might be wise to resurface swiftly. Active sonar, for all its marvels, can pose unexpected risks to those who find themselves in its path.