Your post is very interesting in light of what a former U.S. Navy friend told me several years ago. He said they (the aliens) have underwater bases in the Atlantic ocean off the coast of Brazil..which would explain the many sightings in the area. He also told me the U.S. Navy was working with the "Aliens" and that the navy had an underwater base constructed with hulls same as used in Nuclear submarines. He said they are huge and constructed such that a submarine can dock underneath to access the base. The guy was not drinking at the time he told me that...and I do know he was in "Non-Destructive Testing" and when welding repairs were done on any sub in the fleet that he had final "sign-off" before it could be put back in service...