Abyss, The
The Abyss was a sci-fi adventure film released in 1989. The Abyss was written by James Cameron and starred Ed Harris as Bud Brigman. The movie received mostly positive reviews back in the day, and turned into a profitable movie for 20th Century Fox.
In this movie, a military sub is lost at sea after it sunk near a fault canyon in the Caribbean. In a race to beat the Russians who are trying to salvage the sub, the US military decides to use an underwater oil platform as a staging area to beat the Russians to the sunken wreck. Before long, the crew begins seeing creatures in the depths that appear to be extra-terrestrial. After a major accident, the Navy Seals Commander because to get a bit edgy, and plans on dropping a nuke into the fault chasm to destroy whatever alien life may be down there.
A nuke is sent into the chasm, and the remaining crew go about the business of disarming it after it gets lodged on a ledge. Heading the effort is Bud Brigman (Harris). Just before Bud runs out of air, an alien takes him even further down into the chasm, and into an alien ship. At the end of the movie, the alien ship rises from the depths, along the surviving military team members.