The oceans and lakes of our planet contain some of the most fantastic and awe-inspiring creatures, plants and land formations. However, very few people ever actually get to see them. Surprisingly, funding for space-travel exceeds oceanic exploration, even though there are many underwater areas that have yet to be mapped.
Snorkeling is a fun recreational activity that provides limited underwater exploration (it also doesn't require certification.) However, it is impossible to explore the deep using only breath-holding methods. Scuba equipment, on the other hand, provides a diver with compressed air that enables deep diving-adventure opportunities!
With normal dive equipment, a diver breathes the compressed air through a mouth piece connected to the air tank on their back. Breathing out, the air goes out through a regulator into the water in the form of bubbles. While this is suitable for recreational diving, some divers do not want to their air-bubbles detected.
This is why military divers wear rebreathers. These advanced scuba devices allow a diver to breathe their own air over and over again.
Of course, due to the carbon dioxide a body exhales with each breath, rebreathing is not a simple process; these items must remove the hazardous gas. They do this through a canister of sodium hydroxide, which reacts with the carbon dioxide to form a solid calcium carbonate. Then, small tanks of pure oxygen replace what the diver has already consumed. Sometimes a mix of nitrogen-oxygen is injected back into the breathing cycle, which is just as safe as pure oxygen. Rebreathers also have built-in microprocessors that regulate the concentration of oxygen in the breathing cycle - too much oxygen can produce a state of euphoria that could impair a diver's judgment, which could be extremely dangerous at 100 ft below sea level!
These innovative pieces of dive equipment come in three types: closed circuit, semi-closed circuit and oxygen. Oxygen rebreathers only carry a canister of pure oxygen as the gas supply, but they are limited to depths that do not require intermittent decompression stops. The closed and semi-closed circuit versions utilize mixed gasses and allow divers to safely go to greater depths.
Besides their stealth-like qualities, rebreathers have several advantages over other dive equipment. For example, they have better gas efficiency. Standard tanks waste oxygen because we do not consume all the gas we inhale - rebreathers replace only the consumed oxygen. They are also lighter - conventional tanks mix oxygen with nitrogen (about 78 percent), which makes for a heavier gas. Rebreathers, on the other hand, don't utilize any nitrogen and are lighter with the same amount of oxygen. Nitrogen is also the major cause of decompression sickness (the bends), so without nitrogen, decompression is less complicated and divers can stay at depths longer than with conventional tanks.
Decompression sickness occurs when nitrogen is absorbed into the bloodstream. At those levels, the gas becomes constricted, but upon ascending, it expands - think of it like opening a can of carbonated soda. If a diver with excess nitrogen ascends to the surface too quickly, the nitrogen will expand. This causes extreme pain and, in some cases, even death. Proper education and decompression stops are required to prevent decompression sickness.
Anne Clarke writes numerous articles for Web sites on gardening, parenting, recreation, and home decor. Her background also includes teaching, gardening, and fashion. For more of her useful articles on scuba diving, please visit Dive Equipment, home to useful information on scuba diving gear and much more.
Article Source: http://EzineArticles.com/?expert=Anne_Clarke
0 comments:
Post a Comment