In many ways the ocean is as different from the land on which we live as is the surface of the moon. The sea is one of the last frontiers, even though it is usually no farther than three thousand miles away from the most isolated areas of the earth.
Just as astronauts have to prepare for their journeys to the moon, those who explore the sea must also prepare for this exciting experience. Sea explorers must understand all the rules of diving and know how each piece of equipment used in underwater exploration works.
In many cities instructions and practice sessions are offered to help those who wish to dive safely. To certify as a diver, a person must pass many requirements to show he understands how to protect himself under the surface of the sea. Man himself is the biggest danger he meets when he is in the water.
In warmer climates diving suits (wet suits) do not need to be worn for protection against cold water. However, a diving suit is the most important piece of equipment worn to insure comfort to the diver. A cold diver can get into trouble because he has to struggle harder and gets tired faster than a comfortable one.
The complete diving suit usually consists of a hood, jacket, chest-high pants, and booties. The suit is made of rubber filled with millions of tiny bubbles. Because of these bubbles the suit not only keeps the diver warm and protects him from scratches, but also causes him to float. For this reason, he must also wear a weighted belt so he can dive beneath the surface of the sea.
A mask, snorkel, safety vest, fins, and breathing or scuba gear are also part of a diver’s equipment.
SCUBA stands for “Self-Contained Underwater Breathing Apparatus.” Breathing equipment safe enough for recreational use has been developed only since World War II. This gear consists of a tank filled with compressed air and a regulator that changes the air pressure so the diver can breathe normally. How long the diver can stay underwater depends on how deep he goes and how hard he works. Jacques-Yves Cousteau, a Frenchman, is probably one of the most famous of the early pioneers of scuba.
A balloon filled with air at the surface of the ocean and then taken 132 feet below would be one-tenth the size it was on top. The ocean pushes in on the balloon and squeezes the air together so it becomes smaller. If the balloon were taken down to a depth of 132 feet and then blown up to its original size, the ocean would push on it less and less as it came up toward the surface of the water. When it reached the top, it would be so big it would pop! Such a balloon would be full of pushed-in or compressed air at 132 feet that would expand against the sides of the balloon until the rubber could no longer hold it.
This same thing happens to a person’s lungs in deep sea or scuba diving. Man’s lungs are like the balloon, so a diver must be sure to go up out of the water very slowly, only about sixty feet per minute, so his lungs won’t pop. A diver must also be sure not to hold his breath as he rises.
Before going beneath the surface, a diver should swim around and get used to the water. He must not only check out the area in which he plans to dive, but he must also check all of his equipment. Knowing these rules for diving safety is necessary for a voyage into the sea.
Entering the water is like leaving the earth’s orbit, and exploring the bottom of the ocean is like discovering a new planet. When you are in the water, you are as weightless as astronauts. You breathe in an area where there is no air, just as if you were in outer space.
A first dive is usually a thrilling surprise. When you finally reach the new planet in your sea voyage, everything is a dull green. Where are the vivid colors? A diver learns that the rays of the sun don’t shine down to this planet brightly enough to bring out colors, but shining a light at this depth is like instant color.
In the supposedly silent world of the sea, a diver can sometimes hear many sounds. There is the comforting gurgle of his own air bubbles, the sounds of other divers, the noise of the propeller of a passing boat, and even the sound of fish chewing on the coral.
Exciting adventures await those who are well-trained, brave, and curious enough to accept the challenge of a voyage into the sea!