The linked site provides an excellent review of both the film and the book that describe the CIA effort to recover the GOLF-II Soviet ballistic missile submarine (K-129) lost on 11 March 1968 at 40-04-05N, 179-57-03E where the water depth was 16,400 feet.

The live-action computer-generated graphics in the film are excellent. They are based on imagery taken of the K-129 wreck by a camera system towed by the USS HALIBUT (SSN-587) and by cameras mounted on the recovery device lowered by the CIA salvage ship, the Hughes Glomar Explorer), a 650-foot ship built in the open in Philadelphia under a cover story that its purpose was to mine the seafloor for magnesium nodules, a story the Soviets bought hook-line-and-sinker. The Soviets even watched the recovery effort from two surface ships without realizing what was going on underwater.

Note: for some reason, the link does not get you directly to the site. Suggest putting "Intelligence in the public literature (K-129)" into a search engine and click on what should be the first site listed:
"The Glomar Explorer in Film and Print - Central Intelligence Agency"