As you can see if you skip to the almost end in the video of the link you will see that the object the team tagged dove to a depth of 6,522 feet before they lost the signal. That is the deepest documented dive of anything they had tagged in years of experience. That depth was almost 7,000 feet deep and I am pretty sure nothing has been documented to dive that low let alone past it. Consider this evidence I have and I genuinely believe that this thing (megalodon) is still living in our oceans at a depth of quite possibly more than 7,000 feet, as the tag was designed to reach the depth it did, and considering how fast it was diving it is quite likely.