That day, the Nautilus (a boat that travels under the water) moved through a special part of the Atlantic Ocean. There is a current of warm water in this ocean. People call it the Gulf Stream (a river of warm water that flows inside the ocean). This warm water moves in a very big circle.
In the middle of this circle, the water is very quiet. This place is the Sargasso Sea (a calm part of the ocean with no wind or currents). It is like a big lake in the middle of the Atlantic Ocean. This area is full of seaweed (plants that grow in the ocean).
The seaweed is very thick. It looks like a green carpet on top of the water. Captain Nemo did not want the plants to break the propeller (the part of a ship that turns to make it move). So, Captain Nemo moved the Nautilus under the water. The plants stayed on top of the waves.
Professor Aronnax looked out of the window. He saw many things in the seaweed. There were old trees from the land. There were also many broken ships. These ships were very old. They were covered in small shells and sea plants.
Professor Aronnax saw many animals in the seaweed too. He saw pink sea flowers and blue jellyfish (soft, clear sea animals). Many fish lived in the seaweed because they liked to eat the plants. The Nautilus stayed in this sea for one day. Then, the ocean became normal again.
The Nautilus traveled for nineteen days. Ned Land was very unhappy. There were no islands in this part of the ocean. Ned Land could not escape from the boat. Professor Aronnax, Ned Land, and Conseil had to stay on the ship.
Professor Aronnax wanted to talk to Captain Nemo. He wanted to ask for their freedom. But Captain Nemo was a difficult man. Captain Nemo said they must stay on the Nautilus forever. He did not want the world to know his secret.
During these nineteen days, the voyage was very quiet. Professor Aronnax did not see Captain Nemo very often. Captain Nemo worked in the library (a room full of books). He read many books about nature.
Sometimes, Professor Aronnax heard music. Captain Nemo played the organ (a very large musical instrument). He played the music at night. The music sounded very sad. The Nautilus was alone on the dark ocean.
On the 13th of March, Captain Nemo wanted to find the bottom of the ocean. The ocean was very deep there. The Nautilus moved down into the dark water. It went deeper and deeper.
The water was very heavy. The steel walls of the Nautilus began to shake. The windows of the room started to bend. Professor Aronnax was afraid. But Captain Nemo was not afraid. He knew his ship was very strong.
They went down 16,000 yards. No man was ever this deep before. Professor Aronnax saw big rocks and dark caves. He wanted to remember this beautiful place. He told Captain Nemo about his wish.
Captain Nemo said they could take a photograph. A man brought a camera (a machine that takes pictures) into the room. The bright electric lights of the Nautilus turned on. The light was very strong. They took a perfect picture of the ocean floor.
Then, Captain Nemo said they must go back to the surface. The weight of the water was too dangerous. He told Professor Aronnax to hold onto something. Suddenly, the Nautilus moved up very fast.
The ship was like a balloon. It moved through the water with great speed. In four minutes, it reached the top of the ocean. The Nautilus jumped out of the water like a fish. Then it fell back into the waves with a loud noise.