Heavy Breathing and Diver Distress

As divers go beyond ten meters, they encounter increased pressure, which doubles at this depth. The body begins to descend rapidly, and for every additional ten meters, the pressure escalates by one atmosphere, causing the body to compress. Air cavities within the body lead to discomfort: ears may ache, and there’s a sensation of chest constriction. An untrained individual may struggle to take in air, even with scuba equipment.

Confusing reflexes arise; while the brain signals the need to breathe, compressed lungs resist. Fortunately, no immediate crisis emerges at this stage. Most casual divers simply cease their descent when they run low on air, while scuba divers are trained to manage breathing effectively under water.

Diving deeper than 20 meters subjects individuals to triple the surface pressure, resulting in considerable discomfort. However, the most significant challenge at these depths is the alteration of human behavior.

Under typical conditions, humans inhale air rich in nitrogen, not solely oxygen. At depths of 2 to 3 atmospheres, nitrogen transforms in the body to a state akin to narcotics, leading to unpredictable behavioral changes. Some may experience euphoria and lose control, while others may be gripped by panic and hallucinations, and some may even lapse into a stupor or faint.

The combination of darkness and cold at 20 to 30 meters exacerbates the situation, as impaired self-control and vision increase the risk of accidents. Untrained divers often remove their masks, leading to fatal consequences.

For shallower dives, the risk can be mitigated by increasing oxygen levels in the tank. However, at 60 meters, oxygen itself becomes toxic to humans.

Freediver's Challenge

Freedivers, who dive without tanks, avoid nitrogen and oxygen narcosis but are limited by their breath-holding capacity. The record for breath-holding stands at 11 minutes, with a maximum depth of 214 meters achieved without gear. However, extreme dives can jeopardize a diver's health.

Scuba divers at such depths rely on specialized gas mixtures to minimize the dangers of narcosis. The primary concern becomes decompression sickness. Under pressure, gas bubbles cannot exit the body and begin to infiltrate tissues. Rapid ascents to the surface can result in bubbles bursting within the blood and organs, leading to severe complications like blood clots and internal bleeding.

Submersible Limits

Diving beyond certain depths necessitates specialized equipment. Without such apparatus, the human body would be crushed by the immense water pressure. Submarines can descend up to a kilometer, with the Soviet submarine Komsomolets reaching depths of about 1,250 meters.

Beyond a kilometer, submarines face pressures exceeding 100 atmospheres, which can cause structural failures. The next stage of exploration involves bathyscaphes. The Challenger, designed to withstand significant pressure, had a hull thickness of 13 cm and a diameter of one meter, with a float filled with special foam.

The Bathyscaphe Trieste, a predecessor of the Challenger, experienced a cracked window at a depth of 8 kilometers, necessitating a shorter stay underwater.

Adapting to Extreme Environments

The extreme pressures at such depths have deterred scientists from undertaking deep dives. Instead, they utilize unmanned vehicles, like the Nereus, that can endure pressures of up to 1,000 atmospheres. Although these machines are also susceptible to destruction, the risks are primarily financial.

Surprisingly, depths once thought barren are home to numerous life forms adapted to the pressure, such as the Mariana slug, which thrives at depths of 7.5 to 8 kilometers.

The first video, "What Happens to Your Body at the Mariana Trench Bottom?" explores the physiological effects of extreme underwater pressure.

The second video, "What Would Happen to Your Body at the Bottom of the Mariana Trench?" delves into the body's reactions and the science behind deep-sea diving.