An interesting thread, especially the Howard Hughes spyship. I remember in the mid? 70's, when in Singapore, the story was out that an American ship built by Hughes was going to scoop up manganese nodules in the Pacific. It was much later I heard about the Jennifer(Azorian) project, and I worked for a while on the same ship off Angola in deepwater roughly 12 years ago.
The USNS Hughes Glomar Explorer, was a deep-sea drillship platform initially built for the United States Central Intelligence Agency Special Activities Division secret operation Project Azorian. This was to recover the sunken Soviet submarine K-129, lost in March 1968 approximately 1,600 miles northwest of Hawaii. After this it was mothballed for a period.
During 1997, the ship was moved to Atlantic Marine's Mobile, Alabama shipyard for modifications that converted it to a dynamically-positioned deep sea drilling ship, capable of drilling in waters of 7,500 feet (2,300 m) and, with some modification, up to 11,500 feet (3,500 m), which is 2,000 feet (610 m) deeper than any other existing rig.One major modification was shrinking the hidden moonpool(designed to house the submarine)to a conventional size. i.e. big enough to allow passage of the subsea stack through the hull. The conversion cost more than $180 million ($264 million in 2018) and was completed during the first quarter of 1998. The conversion of the vessel from 1996-1998 was the start of a 30-year lease from the U.S. Navy to Global Marine Drilling at a cost of US$1 million per year ($1.5 million per year in 2018). Global Marine merged with Santa Fe International Corporation during 2001 to become GlobalSantaFe Corporation, which merged with Transocean Inc. during November 2007 and operated the vessel as GSF Explorer. The vessel was scrapped in 2015. Apologies for boring everyone but having worked on the vessel I thought I would flesh the story out a bt more.