Unidentified Submerged Objects and Underwater Bases

There are many books on UFOs and Aliens but most are in the air or over the land. However, you might not be aware that there are also many UFO sightings underwater, or over water. There are even some strong claims of UFO and/or Alien bases underwater. Over 71% of the surface of the Earth is covered in water, much of which is in the Earth's Oceans. So it makes sense that Aliens visiting Earth would hide in the water or even build bases there. Yes-there are reports from several places of poss...