Breakthrough in diving
Want to explore the underwater world? Strap on some scuba gear! By Ellen Whyte
Find words that mean: educated (skilled), secret agent, enthusiastic
The aqua-lung was invented by Frenchmen Jacques-Yves Cousteau and Emile Gagnan. Gagnan was born in 1900. He trained as an engineer and worked for Air Liquide, a company that makes specialised compressed gas for divers, chemical companies and other industries.
Born in 1910, Cousteau began his career as a second lieutenant in the French navy. He worked as a gunner during the second world war and was also a very successful spy.
After the war, Cousteau became an oceanographer, filmmaker and avid environmentalist. His documentaries are world famous.
Both Gagnan and Cousteau created many different tools for underwater use. But the aqua-lung is the most famous.
Fill in the gaps with these words: bubbles, ascend, converts, increases
As you go deeper under the surface of the ocean, pressure ____________________. This pressure can have some strange effects on the human body.
Divers who travel too quickly can suffer from burst eardrums or ruptured blood vessels. Pressure changes also cause a sickness divers call the bends.
Under normal circumstances, our bodies contain liquid nitrogen. When our bodies are put under pressure, this liquid nitrogen _________________________ into a gas.
As this gas ______________________ through joints, tissues and organs, it can cause anything from mild pain to death.
In order to avoid the bends, divers have to descend and _________________________ very carefully and slowly.
Choose the right antonym (opposite): shallower, less, safety
Free-divers try to dive deeper for longer than anyone else - without any scuba or breathing gear. Some free-divers use fins to give them that extra push when they submerge. Some drop a weighted rope, and use this as a guideline to travel up and down.
Some use weights to descend, and release them when they want to move back to the surface. A few use no tools whatsoever. Because of the danger involved, free-diving is called an extreme sport.
Choose the correct alternatives
The idea of trapping air in a capsule and exploring the underwater world is ancient. Greek philosopher Aristotle wrote descriptions of diving bells about 2,400 years ago.
In 1600, engineers started making wooden diving bells with glass windows. Sailors on the surface sent down barrels of fresh air at intervals but the most crews could submerge/emerge was for just 15 minutes.
British engineer John Smeaton fixed that problem when he fitted his diving bells with an air hose and a pumping system in 1788.
While diving suits with an air hose leading to the surface were designed/designated from 1838 onwards, few were made. The air hose that let the divers breathe also meant they couldn't move very far.
Diving was a difficult, dangerous business until 1943 when French naval engineers Jacques-Yves Cousteau and Emile Gagnan designed the aqua-lung.
Filled with repressed/compressed breathing air, the aqua-lung could be carried on the diver's back. This new tool allowed divers to move around freely for an hour or more.
Used by marine biologists, ship inspectors, engineers and millions of eco-tourists, the aqua-lung revolutionised diving.
Bottlenose dolphins dive to 50m and stay down, on average, three minutes. But sperm whales have been known to dive down 3,200m and stay down for almost two hours!
The No Limits free-diving world records are held by Herbert Nitsch from Greece who went down 214m and Tanya Streeter from Grand Cayman who reached 160m. They can hold their breath for up to six minutes!
The deepest dive took place on January 23, 1960 when Jacques Piccard and Don Walsh travelled 10,916m down the Mariana Trench in a submersible called the Trieste. During the eight-hour journey up and down, they spent 20 minutes on the ocean floor, spotting sole, flounder and other deep-ocean creatures.
Answer the following questions. To test your memory, try answering without referring to the text. If you can't remember the details, read the piece again.
1. Wooden diving bells with glass windows were built in:
2. In 1788, John Smeaton created a:
a. wooden diving bell
b. the first personal diving suit
c. diving bell with an air pump
3. An average scuba tank holds about:
a. 30 minutes of air
b. 60 minutes of air
c. 120 minutes of air
4. Sperm whales can dive:
a. 30m below the surface
b. 300m below the surface
c. 3,000m below the surface
5. Free-diving is called an:
a. extreme sport
b. entertainment sport
c. adult sport
6. World champion free-divers can hold their breath for:
a. four minutes
b. six minutes
c. eight minutes
Choose correct alternatives: submerge, designed, compressed
Find synonyms: trained, spy, avid
Fill in the gaps: increases, converts, bubbles, ascend
Choose antonyms: deeper, extra, danger
Quiz: 1. b, 2. c, 3, b, 4. c, 5. a, 6. b