Stars and Stripes Published: April 19, 2010 SEOUL — Two U.S. ships have left the site where a South Korean patrol ship exploded and sank last month as efforts to recover pieces of the ship wind down. The Hawaii-based USNS Salvor remains in the Yellow Sea to assist in the search for debris from the Cheonan. A 16-member U.S. salvage-and-rescue team and a six-person u..