An oceanic question

[Jehanne]

The Challenger Deep is the deepest known area of the ocean.

But I was just thinking, is it at all possible for there to be parts of the ocean where there is no bottom seabed? Is it possible for the ocean to span downward all the way to the opposite side of the globe?

It's a great question, how much water lies below the crust of the Earth:

https://en.m.wikipedia.org/wiki/Deep_Carbon_Observatory

and, with it, life. What amazes me is that there are bacteria, via Darwinian natural selection, that have slowed their metabolism down to thousands of years for cell division to survive deep underground.