Scientists have found that oceanic manta rays routinely make extreme dives of more than 1,200 meters – three-quarters of a mile – but it's not to feed, nor is it happening everywhere in deep water.

Until a few years ago, not many people paid much attention to the extreme sport of free diving. That's where a swimmer packs as much air as they can into their lungs and plunges as deep as they ...

Giant oceanic manta ray (Mobula birostris) and scuba diver in San Benedicto Island, Revillagigedo, Mexico. (Photo by: Luis Javier Sandoval/VWPics/Universal Images Group via Getty Images) The first ...

Many marine species are no strangers to the depths of the oceans. Some animals, like certain sharks, tuna, or turtles, routinely perform extreme dives, whereas for other species such behavior has been ...