When Anthony O’Sullivan joined Nautilus Minerals (LON:NUS) in 2005 his expertise and earlier experiences in leading base metals exploration at mining giant BHP Billiton were put to the test. For Nautilus, and O’Sullivan, the years that followed were spent finding answers to the complex geological, engineering and financial challenges of drilling for copper and gold at 1,500 metres under the sea off the coast of Papua New Guinea. Bringing together the best expertise in international mining and offshore oil and gas exploration – together with a mining lease that was finally issued this month – Nautilus is now closing in on plans to begin production.