Just a few generations ago, Jacques Yves Cousteau and his colleagues invented the aqualung, a portable device for breathing underwater that paved the way for scuba diving as we know it today. Scuba gear has allowed people to explore parts of the world that had never been seen before.
As a consequence of this unprecedented exploration, we have learned new things about the way that the human body and mind react to extreme conditions. It wasn’t too long after Cousteau and his friends began swimming down into the ocean’s darker regions that they began to experience the rapture of the deep.
The rapture of the deep is caused by a physiological condition called nitrogen narcosis. After descending to about a depth of about 100 feet underwater, the high pressure of the water pressing in on divers’ bodies and the air that they breathe causes them to inhale a much greater proportion of nitrogen than they would at the surface. This excess nitrogen interacts with the nervous system, producing an alteration in divers’ consciousness.
Although nitrogen narcosis is the cause of the rapture of the deep, the rapture itself is distinct from its physical causes. It’s an emotional experience that emerges from the confluence of the physiology of nitrogen narcosis and the deep underwater setting into which divers descend. Divers report experiencing a kind of euphoria in which their anxiety about the risks inherent in swimming deep under the surface of the ocean fade away. They feel a sense of confidence and comfort being deep underwater, as if they belong there and no longer need to worry about attending to details such as keeping track of the amount of air that remains in their tanks. Sometimes, rapture of the deep includes hallucinations and unclear thinking. When it’s experienced as a rapture, the feeling is pleasant.
The rapture of the deep shares in common with summit fever the willingness to take risks that would in other settings be rejected as too dangerous. However, while summit fever is manifested as an urge to push beyond the limits of one’s physical abilities, the rapture of the deep brings a radical feeling of acceptance. Rapture of the deep is much less aggressive than summit fever. While summit fever requires strenuous physical exertion to rise to an unsafe height, hanging on with desperate exhaustion to every foot of elevation that is gained, the rapture of the deep is experienced when a diver lets go of fear, allowing gravity to do its work in a gentle manner, with the soft grip of water seeming to embrace and support every inch of the diver’s body, providing an impression of a welcoming presence rather than imminent death.
