https://en.wikipedia.org/wiki/Project_Azorian
The recovery operation in international waters about six years later used mining for manganese nodules as its cover. The company was nominally owned by Howard Hughes, secretly backed by the CIA, who had paid for the construction of the Hughes Glomar Explorer.[5]
The Norwegians just permitted the first offshore nodules mining in their EEZ for REE elements and manganese is the main metal of those nodules.
That was a CIA cover the nodules are there fans in most deep ocean plains as well.
https://www.bbc.com/news/science-environment-67893808