2. THE
OCEAN

3. Three fourths of the Earth is covered by water
Three fourths of the Earth is covered by water. The water is divided into four main oceans, the Atlantic, Pacific, Arctic and Indian Oceans.

4. The land under the oceans is like the land above
The land under the oceans is like the land above. It has mountain ranges, ridges, valleys, volcanoes, plains and trenches

5. You can see the mountain ranges that run under the oceans.

6. Surrounding nearly all continents is a shallow extension of the continent known as the continental shelf. This shelf is relatively shallow, tens of meters deep compared to the thousands of meters deep in the open ocean, and extends outward to the continental slope where the deep ocean truly begins.
The continental slope connects the continental shelf and the ocean basin.

9. Deep water is inhospitable for human divers and other animals because it's cold and dark, and the weight of water overhead exerts intense pressure. Many animals can withstand the harsh conditions at surprising depths, but humans need the protection of mechanical divers.

10. OCEAN RESEARCH

11. SCUBA Dive 475 ft
Jim Diving Suit Untethered Dive 1968 ft
1969, Grumman Aerospace Corporation's research submarine Ben Franklin NR-1, the Navy's nuclear submarine
RMS Titanic's Final Resting Place
DSV Alvin 13,124 feet
Jason (robotic submarine) 19,685 ft
Deepest Recorded Fish 27,460 ft
In 1960, the US Navy sent the Trieste (a submersible - a mini-submarine designed to go really deep) down into the depths of the Marianas trench, 35,813 feet

12. Research vessel
FLIP, short for Floating Instrument Platform, is a 355-foot (108-meter) spoon-shaped buoy. As a buoy, or float, FLIP needs another ship to pull it to a research site. Once in place, FLIP flips. The long tube-like end, or spoon handle, has special tanks, called ballast tanks. These tanks are flooded with 700 tons of seawater, causing them to sink. As this end of FLIP sinks, the other end, kept afloat with air tanks, rises out of the water. Crew members and scientists, on board while FLIP flips, simply step up onto the walls as the walls become decks. In just 20 minutes, FLIP is in a straight up-and-down, or vertical, position, with 300 feet (91 meters) of the ship underwater and 55 feet (17 meters) out of water.

14. In 1996, H.O.T. completed Deep Flight I (DFI), an experimental, one-person submersible
In December 2002, HOT built and completed testing the Deep Flight Aviator, a 2-person winged submersible purpose-built to fully explore the concept of underwater flight

15. The Marianas Trench
or 'The Challenger Deep' It's the deepest spot in any ocean of the world. It is located in the Pacific Ocean, just east of the Phillippines.

16. Many strange creatures live in the perpetual dark and crushing pressure of this deep ocean floor
Fish of the deep ocean include some of the most unusual and least-known fish in the world. Many of them have large eyes, huge mouths, fanglike teeth, and light organs that flash on and off in the dark waters of the depths. Most deep-ocean fish seldom, if ever, come to the surface.

18. OCEAN
CURRENTS

19. Driven by forces such as wind, tides and gravity, currents keep our oceans in constant motion. Currents move large amounts of water great distances.

20. TIDES

21. The most important driving force behind tides is the gravitational pull of the moon. Besides the sun and moon, the shape of the coastline, depth of the water and features on the ocean floor all affect tides.

22. HIGH TIDE
LOW TIDE

23. WAVES

25. Everything from earthquakes to ship wakes creates waves; however, the most common cause is wind. As wind passes over the water's surface, friction forces it to ripple.

26. CORAL
REEF

27. The Great Barrier Reef, the world's largest coral reef, extends about 1,400 miles (2,300 kilometers) along Australia's northeast coast. Its approximately species of colorful coral attract many divers.

29. Amazing colors and shapes and thousands of fishes make coral reefs one of the most spectacular underwater places for people to visit. Each reef is completely unique in its shape and the kinds of animals that call it home. A great number of plants and animals that live in coral reefs have not been studied, or even named, yet.

30. THE END