jules verne

I thought 20,000 Leagues Under the Sea was a great book! Like his book about the moon, I wonder if Verne accurately describes what the bottom of the ocean is like. I don't know much about the oceans and seas of the world, so is there any proof that Verne predicts what the bottom of the oceans looked like before the development of technology to go to those depths. And are their secret societies of people like Nemo and the scientist in to Journey to the Center of The Earth, who explore the hollow earth clandestine, perhaps like Nemo, not letting people know about their wherabouts. He predicted many things, like Life in Paris in the 20th century, and his predictions of life now is accurate. Thanks!