Digital chart error may have led to USS Guardian running aground on reef

Posted at 10:50 AM, Jan 21, 2013

A digital chart used by the USS Guardian misplaced the location of the reef the ship struck by about eight miles.

A day after the grounding  the Navy directed ships to ‘operate with caution’ when using similar electronic charts and compare the map data with paper charts, according to the Navy Times.

The Guardian struck the reef on January 17th, and the Navy has evacuated the crew from the ship after initial attempts to free it failed. Vice Adm. Scott Swift, the U.S. 7th Fleet commander, issued an apology for damaging the Tubbataha Reef on Sunday. Home to a vast array of sea, air and land creatures, as well as sizable lagoons and two coral islands, Tubbataha Reef’s Natural Park is a UNESCO World Heritage site.

The Digital Nautical Charts (DNC) used by the Guardian and most Navy ships are produced by the National Geospatial-Intelligence Agency (NGA), a largely secret organization headquartered in Springfield,Va.

The DNC charts come in several versions. “General” and “coastal” versions are used in open areas such as the Sulu Sea, and “approach” and “harbor” versions are used for operating in and around harbors. According to an NGA memo sent to the Navy on Jan. 18, the error was in the coastal DNC, apparently in use on board the Guardian at the time of the grounding.

The general DNC and hardcopy charts show the reef’s location correctly, NGA said.

Letitia Long, the agency’s director, told the Navy that the coastal DNC charts would be corrected by Jan. 30, and advised ships not to use the Sulu Sea charts until then.

Read more at the Navy Times.