“The depths below the ocean’s surface comprise a staggering 95 percent of the Earth’s living space, and much of it is unexplored by humans. To put into perspective just how deep the oceans go, this XKCD comic, (hi-res image). Most of the ocean doesn’t even see sunlight. Even scientists aren’t familiar with everything that’s down there.”
XKCD is a comic strip that deals with many intellectual issues, but it can also be a wealth of quality scientific information. This infographic on the oceans is staggering.