Forum Thread: 5 Most Mysterious Underwater Sounds Ever Recorded

The ocean is a mysterious place. Humans have only explored 5% of it, and two-thirds of ocean species remain unknown. Just imagine what could be lurking in the deep. Today on ApexTV we look at the 5 most mysterious underwater sounds ever recorded. From mysterious sounds that could be from undiscovered creatures, to mysterious underwater sounds that sound like a train, the ocean is a very mysterious place.