The Great Wonders Beyond the Great Reef

What lies off Australia’s Great Barrier Reef, in the Coral Sea? The region was mostly unexplored and uncharted until a recent expedition searched its dark waters, uncovering an abundance of life, weird geologic features and spectacular deep corals. The deepest forays reached down more than a mile.

The expedition was organized by the Schmidt Ocean Institute, founded by Eric Schmidt, the former chairman of Google, and his wife, Wendy. Its centerpiece was a ship, nearly the length of a football field, that could map the remote seabed with beams of sound and deploy tethered and autonomous robots to capture close-up images of the inky depths.

“It blew our minds,” Robin Beaman of James Cook University, the expedition’s chief scientist, said in an interview. “We’ve gone from literally knowing nothing to knowing a lot.”

An earlier leg of the expedition found a gelatinous creature whose length was estimated at 150 feet — potentially the world’s longest example of oceanic life.