The grounding of a mega ship could result in a cargo loss of up to US$4 billion, the insurance industry warns. 

It's a possibility that cannot be ruled out as the world has better maps of the surface of Mars and the moon than of the bottom of Earth's ocean, according to a NASA oceanographer


It "could take two years to remove all the containers from a 19,000-TEU ship in the event of an incident, assuming that it was possible at all," Allianz Global Corporate & Specialty Insurance wrote in its Safety and Shipping Review.

The risk of such a catastrophic loss only increases as more mega ships begin calling at ports around the world that have never seen ships of that length, width and depth.

A new study by the Global Marine Practice at insurance brokerage Marsh highlighted that surveys of ocean depths are inadequate or non-existent in large expanses of the world, with many areas either having no survey or having surveys that haven't been verified since being done more than a century ago, reported IHS Media

Navigation routes to the Panama Canal, for example, have been the same for years, with cargo vessels following "tried-and-tested pathways," the Marsh report found. But what's safe for a vessel requiring 40 feet of draft may not be safe for one requiring nearly 55 feet.

"We have better maps of the surface of Mars and the moon than we do the bottom of the ocean," the Marsh report quoted US oceanographer for NASA, Gene Feldman, as saying. "We know very little about most of the ocean."