Today we’ve only explored about 3 percent of what’s out there in the ocean. Already we’ve found the world’s highest mountains, the world’s deepest valleys, underwater lakes, underwater waterfalls … . There’s still 97 percent, and either that 97 percent is empty or just full of surprises.

Source:

"Underwater Astonishment." TED2007. Mar. 2007. Conference Presentation.

Additional Information: This quote by oceanographer David Gallo is from Gallo's 2007 TED Talk about the amazing creatures that live far below the ocean's surface. The quote means that in contrast to the rest of the natural world, humans have explored hardly any of the ocean -- 97 percent of the world's oceans remain unexplored. Watch Gallo's TED Talk, which contains amazing video footage of the bioluminescent creatures that inhabit the ocean's inky depths: David Gallo - Underwater Astonishments

“Underwater Astonishment.” TED2007. Mar. 2007. Conference Presentation.