Part of a series of documentaries exploring unexplained alien mysteries from throughout history. Unidentified submersible objects are well-documented by the military. While they often defy the laws of physics in oceans and lakes, are they extraterrestrial? #aliens #testimony #ufo #encounter #incident #report #unidentified #mystery #evidence #proof #thetruthishere #thetruth #alien #eyewitness #underwater #undersea #secret #coverup #usos