[Light Speed]

Navy to chart ocean floor after tsunamiNavy cartographers say navigation through the Indian Ocean will be problematic for years due to last month’s violent earthquake and deadly tsunami, both of which altered normal shipping routes.
Old charts may have caused fatal accident of U.S. nuclear submarine
Seafloor Still About 90 Percent Unknown, Experts Say

[GATOR NAVY]

Your last link points to the real cause of this accident. Although the possibility of a seamount had been noted years earlier from satellite photos, no one had ever taken a survey vessel there and investigated it.

[jocko12]

This sounds like a Navy CYA drill.