When you stop to think about it, we know less about the oceans of Earth than the space immediately surrounding the planet.
Because unlike space, we can't see through the ocean or use satellites to explore it.
That's why the Ocean Observatories Initiative started up... to place sensors off both coasts of the United States, to track a broad array of information.
A crew from Oregon State University recently placed the final sensor in the Pacific.
We hear from a couple of the OOI scientists about what happens now.