Elephant seals amaze scientists with their ability to sleep 1,200 feet deep under the ocean to avoid predators

• Elephant seals drift downwards in a "sleep spiral" when deep diving in the ocean, a new study found.
• Sleeping while deep diving allows the seals to avoid predators, scientists believe. 
• The scientists recorded the brain waves of 13 young female seals in California as part of the study.

Elephant seals drift downwards into the ocean in a "sleep spiral" to catch up on sleep while on months-long foraging trips but are programmed not to drown, according to a new study.