Science Fair Project Encyclopedia
Scuba diving is the use of independent breathing equipment to stay underwater for long periods for recreational diving and professional diving. Generally the diver swims underwater, but walking and the use of diver propulsion vehicles is possible while breathing from scuba equipment. The word 'scuba' is an acronym for Self Contained Underwater Breathing Apparatus, although it is grammatically acceptable to refer to 'scuba equipment' or 'scuba apparatus' in conversation.
Issues that diving poses
Also see Diving disorders for a longer description of these issues followed by an extensive discussion of physical and medical risks.
Equipment to allow underwater breathing
The two most common types of equipment are:
- surface supplied diving, where the diver's breathing gas (usually air) is pumped down from the surface. Standard diving dress is a historically interesting type of surface supplied diving equipment.
- scuba, where the breathing gas supply is carried by the diver.
There is no single optimal breathing gas mix for every type of dive
A wide variety of breathing gas mixes have been used for diving. Each mix must contain sufficient oxygen to sustain life and consciousness. Mixes may contain other gases such as nitrogen and helium. As the concentration of gases increases with the depth of the dive and some gases are toxic at high concentrations, the design of breathing gas mixes depends on the depth of the dive.
Need to avoid injury caused by changes in water pressure
Pressure injuries are called barotrauma. They are caused by pressure differences between the outside and trapped air spaces inside the diver or the diver's equipment. To avoid them, the diver "equalises" the pressure in all air spaces with the surrounding water pressure when changing depth.
Need to avoid decompression sickness
Need to see underwater
Controlling buoyancy underwater
Avoiding losing body heat
Avoiding skin cuts and grazes
Diving suits also help prevent the diver's skin being damaged by rough or sharp underwater objects and marine animals.
Diving longer and deeper safely
There are a number of techniques to increase the diver's ability dive deeper and longer:
- technical diving - use of SCUBA breathing gases other than air
- surface supplied diving - use of umbilical gas supply and diving helmets
- saturation diving - long-term use of underwater habitats under pressure and a gradual release of pressure, over several days, in a decompression chamber at the end of a dive
Being mobile underwater
- The diver needs to be mobile underwater. Personal mobility is enhanced by fins worn on the feet and Diver Propulsion Vehicles. Other equipment to improve mobility includes diving bells and diving shots.
- Timeline of underwater technology
- Diving equipment
- Diver training
- Diving locations
- Diving activities
- Diving physics
- List of SCUBA magazines
- DIR diving
- Diving Glossary
- Divers Alert Network
- Brief history of diving - From antiquity to the present.
- Top Scuba Sites - Scuba sites as ranked by user popularity.
- Scuba Diving Guide - Information for scuba divers.
- Scuba Monster - Scuba Usenet discussions and archive.
- NAUI Worldwide is the world's oldest not-for-profit membership training agency organized solely to support and promote dive safety through education.
- Australia Underwater - All about diving in Australia - includes photo gallery from all around Australia.
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details