Whales use their ears to get around in the dark depths.

CNN: waves

At least 15 of 33 miners have emerged from the depths of a dark, claustrophobic hole after 69 days of being trapped underground.

FORBES: Connect

Last night during the depths of the storm, the television was dark and silent.

FORBES: The Big Lesson of #Sandy: Connectivity Matters in an Emergency

In the absence of light, life in dark waters can also depend on organic substances dead or alive reaching the depths of the ocean.

UNESCO: MEDIA SERVICES

And we have said from the beginning that the road out of the dark place we were in when this President took office in terms of the economic recession, the depths of the recession we were in, was not going to be smooth every step of the way.

WHITEHOUSE: Press Briefing