From the authoritative coltoncompany.com:
The famous ship, built by Sun Ship in 1973, at a cost said to have been at least $350 million, for the purpose of recovering a sunken Soviet submarine, is being flagged out. Now called the GSF Explorer, it was converted to a regular drill ship in 1997, after the Navy leased it for 30 years to Global Marine's successor company, Global Santa Fe, which is now part of Transocean. The Congress authorized its sale to Transocean in 2002, for "a fair and reasonable amount determined by the Secretary of the Navy". I'm told that they only paid $15 million, which is hard to believe: can anyone confirm this or provide the true figure? There now seems to be nothing to stop Transocean taking her foreign. Of course, Transocean reflagged itself last year, when it moved from Houston to Geneva and became a Swiss corporation. April 28, 2010.