Royal Navy helicopters carrier HMS Ocean sails through the Thames Barrier on the River Thames in London to dock at Greenwich as part of London 2012 Olympic preparation security exercise, Friday, May ... more 
Royal Navy helicopters carrier HMS Ocean sails through the Thames Barrier on the River Thames in London to dock at Greenwich as part of London 2012 Olympic preparation security exercise, Friday, May 4, 2012. The HMS Ocean forms part of a co-ordinated defence against possible threats to the London 2012 Olympic games, involving all three British armed services. (AP Photo/Sang Tan) less 
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Associated Press | Photo By Sang Tan
Mon, May 7, 2012 7:00 AM EDT