Versions of the submarine have existed since the seventeenth century, but it was not until the first World War that the underwater craft began to be widely used. Traditionally, we associate submarines as a part of a country’s naval power, but many submarines are in fact used by civilians in order to do things like scientific research, salvage operations, and deep sea or sea floor exploration. James Cameron has directed some of the most iconic movies in cinema history, including Titanic and Avatar, and because of these movies he possesses a net worth of almost 1.8 billion dollars. What many people may not know about Cameron though, is that he enjoys marine biology and going on deep sea diving expeditions, which is why he bought his own one-man operated submarine to take out whenever he wants. The submarine that he bought is known as the Deepsea Challenger, and it is a good thing that Cameron is a highly successful Hollywood director, because a submarine like that costs around 1.5 million dollars to buy.