A U.S. military dive team has begun pulling artifacts from the floor of Subic Bay, where a Japanese prisoner transport ship sank in December 1944 with more than 1,600 Allied prisoners of war packed in its holds. The recovery is part of what the Defense POW/MIA Accounting Agency has called the most complex underwater operation in the history of its missing-personnel program. A 15-person dive team began work in February from the salvage vessel USNS Salvor , targeting the wreck of the Oryoku Maru ,