Underwater diving
Underwater diving is an activity that enables individuals to explore submerged environments using specialized equipment, including scuba gear and diving bells. This activity can be pursued recreationally, allowing divers to interact with marine life and observe underwater landscapes, or professionally, encompassing roles in underwater construction, research, and rescue services. The evolution of diving technology began in 1535 with the introduction of the diving bell, which allowed divers to access the seafloor for salvage operations. Subsequent advancements led to the creation of wearable diving apparatus in the 18th century and, eventually, modern scuba tanks that provide divers with a portable supply of compressed air.
Diving requires the use of specific tools, such as scuba masks that prevent water ingress and allow visibility, and regulators that provide breathable air at safe pressures. Divers must be aware of the risks associated with depth changes, particularly decompression sickness, which can occur if they ascend too quickly after deep dives. As a versatile activity, underwater diving not only serves as a form of recreation but also plays a vital role in various professional fields, including law enforcement, construction, and scientific research, necessitating a high level of training and adaptability to diverse underwater conditions.
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Underwater diving
Underwater diving is an activity that makes use of specialized equipment, such as diving bells and scuba gear, to allow humans to spend extended periods of time in underwater environments. Some individuals practice underwater diving as a hobby. They dive to interact with ocean wildlife and view interesting underwater landscapes. Others participate in underwater diving as part of their professions, working in underwater construction or rescue services.
Background
The first specialized underwater diving equipment, the diving bell, was developed in 1535. Diving bells were large, hollow objects suspended from ships. Water pressure forces trapped air into the object, creating a pocket of air even when the device is entirely submerged. Divers rode diving bells to the seafloor, then returned to the bell whenever they needed air. This allowed divers to scavenge shipwrecks and search for lost valuables.
In 1771, the first wearable diving device was invented. It featured a brass helmet connected to a set of bellows. The bellows were used to pump fresh air from the surface into the helmet. Only a small amount of air could be pumped into the helmet at once, making long dives with the device impractical. Other inventors experimented with this design, improving it over the following decades.
The first commercial diving apparatus was originally intended as firefighting equipment. The first helmet allowed firefighters to walk into dangerous smoke-filled buildings by ensuring they had a constant supply of fresh air. When coupled with a specialized suit and weighted shoes, the apparatus allowed a diver to walk along the bottom of a body of water. Many divers quickly realized the suit's potential and began using it for salvage operations. Later modifications to the suit, such as a fully waterproof helmet, allowed divers to execute complicated maneuvers.
In 1865, the first steel tanks filled with compressed air were developed for divers. They allowed divers to carry their own air supply underwater, rather than relying on air pumped from machines on the surface. While safer than using pumped air, such tanks could only carry a limited supply of air. Over time, these tanks developed into modern scuba tanks.
Overview
Scuba divers use a variety of special tools for diving. The first tool many scuba divers learn to use is the scuba mask. A properly fitting scuba mask forms an airtight seal around the diver's face. This keeps out water, allowing the diver to see underwater without difficulty. However, it also allows the diver to adjust to changes in pressure as he or she descends into the water.
An ill-fitting scuba mask is problematic for divers. If a mask does not fit, it may fail to seal properly. This causes water to leak into the mask during a dive, obstructing vision and forcing divers to devote valuable dive time to clearing their view.
To breathe underwater, most divers utilize a scuba tank. Modern scuba tanks have a similar oxygen to gas ratio as normal air, but this air is heavily compressed. The more air that can be safely compressed into the tank, the longer the diver will be able to breathe underwater. The compressed air passes through a specialized tube to a device called a regulator. The regulator decreases air pressure in a controlled and safe manner, allowing divers to comfortably breathe the compressed air.
Many scuba tanks and regulators are paired with a dive computer. Dive computers are small devices that track drivers' depths, adjusting the pressure and nitrogen levels of their scuba tanks to compensate for external water pressure. Some dive computers also track the amount of breathable air remaining in divers' scuba tanks, letting them know how much longer they can remain underwater.
Experienced divers often tailor their equipment and training to a specific type of dive. Open-water scuba diving is the simplest style of scuba diving. It simply requires that the diver descend to moderate depths in clear conditions. Divers may conduct open-water dives to survey the ocean floor, interact with wildlife, or to practice for more difficult dives.
Some scuba divers carry out open-water dives in the dark. Night dives allow underwater divers to interact with many aquatic species that hide during the day. Powerful, specialized lights are essential to night dives.
Especially deep dives require special skills. Divers ascending from deep water must carefully time their swim back to the surface to avoid decompression sickness. Decompression sickness, also called the bends, occurs when the increased pressure from diving causes nitrogen to dissolve into the diver's bodily tissue. If the diver rises too rapidly, the sudden lack of pressure can cause the nitrogen to form into bubbles inside the body. The risk of decompression sickness increases with the depth of the dive and the length of time spent underwater.
While many individuals explore underwater diving as a hobby, others pursue it as a career. Some professional scuba divers work with the police. They search the bottoms of rivers, lakes, and oceans for evidence and missing objects. Some police divers also serve as rescue crews for individuals trapped underwater.
Other professional divers work in construction. Large aquatic structures, such as offshore oil and gas rigs, require much of their bulk to be submerged under the ocean's surface. Any repairs or maintenance to these structures must be carried out by specially trained underwater divers.
Many scientific pursuits also require that researchers be trained in underwater diving. Aquatic researchers must spend extended periods underwater. Using scuba gear, researchers collect data, conduct experiments, and survey local aquatic wildlife. Because scientific divers are often diving in unfamiliar conditions, they must be skilled, focused, and adaptable.
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