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Diamond Offshore Drilling, Inc.

An offshore drilling contractor that runs semisubmersible rigs and drillships, punching deep wells beneath the ocean for oil and gas companies. It traces back to 1964, when Texas rancher Don McMahon took over a bankrupt rig firm and renamed it Diamond M after his own ranch, Diamond M Acres. In 2024 the company became part of Noble Corporation. Fun fact: its famed rig Ocean Victory gave its name to the whole "Victory class" of semisubmersibles.