The Abyss (1989)

A civilian diving team is tapped as the most viable option to respond as possible rescuers to a US nuclear submarine sinking. To aid their efforts, a small group of Navy SEALS is dispatched, but they have an agenda to which the civilian team is not privy. To make ratchet up the stakes even more, a dangerous storm rages on the surface, which causes damage to the underwater rig, adding to the natural tensions already being felt by everyone involved. Throw in a little wonder in the form of never-before-seen underwater species and you've got a plot that's stuffed to bursting.

I remember being wowed by this when I first saw it more than 30 years ago. Though effects have come a long way, this still really packs a punch. There's some stiff acting and clunky dialogue, but the action scenes work and the underwater world is breathtaking. 

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