The research submersible Alvin uses bright lights to illuminate the dark seafloor. Built in 1964, it has made more than 4,400 dives. It can carry two scientists and a pilot as deep as 4,500 meters (14,764 feet). Alvin is being updated in order to dive deeper - up to 6,500 meters. More about deep ocean exploration can be found in our Deep Ocean Exploration featured story.