The 25-year-old U.S. Navy minesweeper, the USS Guardian, ran aground near the Philippines at the Tubbataha Reef due to a problem with its mapping systems. The ship's systems located the reef elsewhere.
In April 2013 Lt. Cmdr. Mark Rice, the Guardian's commanding officer, as well as the navigator, assistant navigator and officer standing watch at the time of the grounding were all relieved by Adm. Jeffrey Harley. Rice was to slated to take command of the Guardian's replacement.
Four fired for marooning minesweeper on ocean reef