Ballard has spent more than thirty years exploring under the sea. He pioneered the use of deep-diving submersibles and has been on more than 120 undersea expeditions. In 1973 and 1974 he explored the Mid-Atlantic Ridge, a huge undersea mountain range in the Atlantic. In 1977 he discovered 2.5-metre worms living in the sea near Ecuador, South America. He also discovered underwater volcanoes off the coast of California in 1979. Ballard was the perfect person to search for the Titanic.