Prior to the early 20th century, pearls were obtained by free-divers who manually swam to the depths of a body of water to retrieve oysters which were then opened and searched for the stones. While pearl diving is largely obsolete, people free-dive recreationally and search for pearls. Pearl diving can be dangerous; in certain instances, it may even be fatal.
Drowning Due to Deep Water Blackout
Drowning is always a danger whenever swimming and diving are concerned. For pearl divers, however, drowning typically came about as a result of deep water blackout, a condition caused by cerebral hypoxia that comes about when a diver surfaces from a deep dive (typically dives greater than 30 feet). In a deep water blackout, the swimmer loses consciousness as they near or break the surface of the water. If the diver does not quickly regain consciousness, death from drowning can result. Because pearl divers typically dove great distances under water to retrieve the pearls, they were especially at risk for deep water blackout.
Decompression sickness is another common risk faced by pearl divers and other deep sea divers. According to the Undersea & Hyperbaric Medical Society (UHMS), as a person dives, oxygen and nitrogen dissolve into the person's body tissues. Excess nitrogen can form bubbles which can get trapped in the diver's lungs as the diver returns to the surface. If these bubbles reach the bloodstream, a person may experience an embolism which results in numerous symptoms such as pain, dizziness, hearing loss, paralysis and unconsciousness. Pearl divers who returned to the surface too fast, thereby not giving the body a chance to diffuse the gas bubbles safely, experienced decompression sickness.
Pearl divers searching for pearls in cold water ran the risk of hypothermia. Hypothermia is caused when the body's temperature drops below a certain level. Symptoms include shaking and blue skin, high blood pressure, slurred speech and memory loss. At extreme levels (when the body's temperature drops below 80 degree Fahrenheit), the diver could lose consciousness, permanently damage the brain or suffer a heart attack.
Dangerous Creatures and Environmental Risks
Pearl divers ran the risk of running into hostile sea creatures such as jellyfish, certain octopuses, sharks and poisonous fish. A diver could not see very easily under the water (even when using a mask and snorkel) and sometimes would put a hand onto a dangerous sea creature, like a venomous sea anemone. Furthermore, simply diving into a rocky region was a danger. The diver could receive cuts or contusions from swimming into the rocks by accident.