I always like to theorize about this kind of stuff, and I think that this idea has a lot of evidence supporting it and can very well be true...
A majority of our oceans are unexplored by humans, and there is already many species that live deep in the oceans that we haven't discovered and that is fact. But the idea that aliens visiting the earth and finding shelter deep in our oceans is a plausible idea.
Video : "Who Lives At The Bottom Of The Mariana Trench?" By "Ridddle"
The video above discusses life at the bottom of the Mariana Trench, which in the past we thought was impossible due to the pressure.
Watch 3:12 through 3:45 if you don't want to watch the whole video.
They talk about some guys that took a submarine into the Mariana Trench and they documented witnessing a disc shaped object outside of their submarine that was noticeably maneuvering and clearly watching them and then soon after disappearing from sight....
A picture of an apparent UFO coming out of the Ocean.
I hope you guys thought this post was cool, I enjoy these "What If" scenarios especially if there is evidence that compliment the idea. This isn't fact by any means, we don't know for sure that there is extraterrestrial life in our ocean, but think about it!
@nexttimetech