My late husband grew up with one of the main divers on the Atocha. They were room mates when he and I first dated. It was fascinating listening to his stories of the search and find. I also got to see a lot beautiful jewelry and coins.
Another good book on the search is by Eugene Lyons. If memory serves a more precise spot where the Atocha went down was discovered by looking in Spanish records. The Spaniards kept very good records but when they were first reviewed by those searching someone did not understand the Castilian dialect they were written in, and originally the wrong spot to search was chosen. When that mistake was discovered they were able to go to the correct area.
Thanks! The moment I had remembered from the NG video years ago was also crucial to the story told in the newer documentary — that the identification of the wreckage was made possible by the manifest of its last cargo, with the numbered silver bars having been weighed.