Deep water photosynthesis , Underwater Falls, Unexplained sound is one of the mystery of the Ocean. According to NOAA Ocean has different sounds “The Bloop,” “Train” and “Julia,”these are the some of the sounds have been captured by hydrophones, or underwater microphones, monitored by the National Oceanic and Atmospheric Administration (NOAA). The decidedly non spooky nicknames for these sounds do little to dispel the mystery surrounding them. In 1997, NOAA 3,000 miles apart picked up one of the loudest sounds ever recorded off the southern coast of South America: the Bloop (which sounds exactly like its name, a bloop). The Bloop mimics marine animal sounds in some ways, but if it were some kind of sea creature it would have to be almost the size of the Eiffel tower for that sound to be heard from 3,000 miles away.