I love The Abyss, fantastic film. It's right on the cusp of cgi and practical effects, too, and somehow ends up looking much better than many films. Notably, it used the first edition of photoshop- the special effects department painstakingly went through and altered individual frames in photoshop to achieve the desired effects in many scenes.

We definitely know less about the deeps than we do about space. And yeah, it's as though we think as a society that what we don't see isn't happening, and as though what we do in one domain can't have rippling effects spreading through other domains.