URGENT: US PPI declines by 0.2% in May    Egypt secures $130m in non-refundable USAID grants    HSBC named Egypt's Best Bank for Diversity, Inclusion by Euromoney    Singapore offers refiners carbon tax rebates for '24, '25    Egypt's CBE offers EGP 4b zero coupon t-bonds    G7 agrees on $50b Ukraine loan from frozen Russian assets    EU dairy faces China tariff threat    Over 12,000 Egyptian pilgrims receive medical care during Hajj: Health Ministry    Egypt's rise as global logistics hub takes centre stage at New Development Bank Seminar    Blinken addresses Hamas ceasefire counterproposal, future governance plans for Gaza    MSMEDA, EABA sign MoU to offer new marketing opportunities for Egyptian SMEs in Africa    Egypt's President Al-Sisi, Equatorial Guinea's Vice President discuss bilateral cooperation, regional Issues    Egypt's Higher Education Minister pledges deeper cooperation with BRICS at Kazan Summit    Gaza death toll rises to 37,164, injuries hit 84,832 amid ongoing Israeli attacks    Egypt's Water Research, Space Agencies join forces to tackle water challenges    BRICS Skate Cup: Skateboarders from Egypt, 22 nations gather in Russia    Pharaohs Edge Out Burkina Faso in World Cup qualifiers Thriller    Egypt's EDA, Zambia sign collaboration pact    Madinaty Sports Club hosts successful 4th Qadya MMA Championship    Amwal Al Ghad Awards 2024 announces Entrepreneurs of the Year    Egyptian President asks Madbouly to form new government, outlines priorities    Egypt's President assigns Madbouly to form new government    Egypt and Tanzania discuss water cooperation    Grand Egyptian Museum opening: Madbouly reviews final preparations    Madinaty's inaugural Skydiving event boosts sports tourism appeal    Tunisia's President Saied reshuffles cabinet amidst political tension    Instagram Celebrates African Women in 'Made by Africa, Loved by the World' 2024 Campaign    Egypt to build 58 hospitals by '25    Swiss freeze on Russian assets dwindles to $6.36b in '23    Egyptian public, private sectors off on Apr 25 marking Sinai Liberation    Debt swaps could unlock $100b for climate action    Financial literacy becomes extremely important – EGX official    Euro area annual inflation up to 2.9% – Eurostat    BYD، Brazil's Sigma Lithium JV likely    UNESCO celebrates World Arabic Language Day    Motaz Azaiza mural in Manchester tribute to Palestinian journalists    Russia says it's in sync with US, China, Pakistan on Taliban    It's a bit frustrating to draw at home: Real Madrid keeper after Villarreal game    Shoukry reviews with Guterres Egypt's efforts to achieve SDGs, promote human rights    Sudan says countries must cooperate on vaccines    Johnson & Johnson: Second shot boosts antibodies and protection against COVID-19    Egypt to tax bloggers, YouTubers    Egypt's FM asserts importance of stability in Libya, holding elections as scheduled    We mustn't lose touch: Muller after Bayern win in Bundesliga    Egypt records 36 new deaths from Covid-19, highest since mid June    Egypt sells $3 bln US-dollar dominated eurobonds    Gamal Hanafy's ceramic exhibition at Gezira Arts Centre is a must go    Italian Institute Director Davide Scalmani presents activities of the Cairo Institute for ITALIANA.IT platform    







Thank you for reporting!
This image will be automatically disabled when it gets reported by several people.



Sci-tech: Self-contained underwater breathing apparatus, or how to be a fish underwater
Published in Daily News Egypt on 23 - 12 - 2006


Respect your body, your equipment, and the Red Sea
Egypt has been blessed with the Red Sea; you can swim in its warm waters, surf its windy swells, or dive its stunning depths. And in attempting to do the latter in bodies of water the world over, we humans have uncovered a life much less ordinary.
Freediving, which relies only on breath-holding, has been around since humanity began. Diving with an air supply likely started with long reeds, the predecessor to the snorkel, but any longer than a meter and it becomes too difficult to breathe against the water pressure.
From the late 1700s to the mid 1900s, various European inventors experimented with improvements to air supply, first manually pumped from the surface and then later becoming self-contained. And as many of us remember from childhood schooling, it was Jacques Cousteau's aqua lung which was the considered the brilliant foundation of today's scuba gear.
If you've been snorkeling already, and intend to again, then you should start buying your own gear, so when the time comes to take the plunge, you're good to go.
A mask and snorkel are a good place to start. A comfortable mask that fits the shape of your face can be hard to find, but once you find it, buy one. Consider splashing out on a snorkel with a closure valve that seals against water, so you don't end up gasping on the pounding waves that could otherwise be sent through your snorkel by the blustery winds of a Red Sea in winter or spring.
Fins are considerably more straightforward, and your best bet is a pair of open-footed ones that you use with a pair of neoprene booties, enabling you to then traipse more comfortably over the reef.
Your remaining equipment - high-pressure tanks holding compressed air, a regulator that supplies air at the correct pressure, a buoyancy vest to be inflated or deflated via your air tanks, and a wet suit - can all be hired from the nearest dive center.
Once you have assembled all this kit, you're ready to swim with the fishes - but not in the mafia sense, so listen up.
As you descend into the shark-laden depths, the squeals you hear may not be due to toothy predators, but rather the reaction of your inner ears to pressure changes. As with chewing bubblegum as an airplane drops altitude to land, blowing gently against a pinched nose can help you equalize the pressure as you descend below the water's surface.
As you go down, the air inside your ears becomes compressed from the extra weight of the atmosphere and the water above, increasing the pressure all around you. The pressure difference should be equalized every meter, or the resulting ruptured eardrum will not just stop you diving for the next while - it will hurt like hell.
As for your breathing apparatus and its air: Oxygen, under pressure, will become toxic - at just over 10 meters if breathing pure oxygen, and at 105 meters if breathing air. This demands that the percentage of oxygen in your tanks be decreased for deeper dives.
Keep in mind that air consists of both nitrogen and oxygen. And as nearly 80 percent is nitrogen, this is the gas that should concern you most while diving. When descending, the increased pressure compresses the body, causing the nitrogen to be intensively absorbed by the blood and dissolved, meaning nitrogen narcosis and its resulting disorientation and feeling of intoxication.
When rising back to the surface, decompression occurs and the ensuing pressure decrease releases the nitrogen gas from the cells and tissues. If the diver ascends too fast, before complete desaturation takes place, nitrogen forms bubbles in the cells and tissues; these dangerous bubbles can plug small arteries and stop the flow of blood to the organs.
Decompression tables, or a dive computer, will tell you how long you can safely stay at a certain depth, and how to safely ascend from various depths with differing durations and breathing mixtures.
Given the difficulties and risks of diving, some may wonder why anyone would go to all this trouble in the first place.
While 'returning to the womb' maybe an over simplification, or exaggeration, of the feeling of breathing underwater, being in such an environment can indeed connect you with positive and powerful emotions. The underwater world can be humbling and affect your view on life itself.
As you emerge from the deep and are walking out from the Red Sea, you might even be so moved as to find yourself collecting some of the many plastic carrier bags that sadly litter so much of the coastline.
Before you get too carried away though with a sense of oneness with your sub-marine brethren, it's best to keep a respectful distance from them - do not touch the fish, or anything in fact. After all, many underwater creatures are masters of disguise, and self-defense, and by the time you realize that spectacular plant is actually a venomous lionfish - "but it's so pwetty . uh . nnngh . aaargh! is all that will follow after its hypodermic needle-like dorsal spines inject you with neurotoxin.
Not that I hold anything against the sea urchin that impaled my hand at 18 m .


Clic here to read the story from its source.