In the early 1900s, the world’s first submarine was built at the end of the Great Depression.
It was called the SS Alabama.
It carried a crew of 10 men and it took about four months to complete the voyage.
In this video, you can see how it took three years to reach the depths of the ocean.
It took six months to reach an underwater cave on the bottom of the Atlantic Ocean, known as the “Deep Tunnel,” in the Atlantic ocean.
The tunnel was made up of concrete, stone, and sand and was built to help the ship move under the sea.
When the Alabama was destroyed in World War II, its crew members were given a special job: digging a tunnel for a new submarine.
The tunnel was about five feet wide and two feet deep, and the tunnel had to be dug through rock and sand to reach a cave called the “Trench of the Earth.”
When the tunnel was completed, the crew of the Alabama used ropes to pull themselves out of the cave, but the tunnel’s end was not visible.
When it came time to build the second submarine, the Alabama sank in the North Atlantic.
The submarine sank in a storm that broke over the ocean floor.
The crew of that submarine went back to the Alabama and dug the tunnel.
It took about six months.
In this video you can watch the crew digging a hole that is only 1 foot deep.
It is only the second tunnel dug under the ocean, and it is now the deepest one ever explored.
The team of researchers who built this submarine are calling it the “Great Deep Tunnel.”
The tunnel is just about the size of two football fields.
It takes about two weeks to complete.