CONTROVERSIAL U.S. RESEARCH VESSEL LEAVES MEXICO

Columbia University's Lamont-Doherty Earth Observatory, which operates the vessel, said that the crew relied on flawed and misleading navigational charts. According to the university, the charts indicated that there was adequate water depth in the location of the grounding.

However, Mexican authorities claim that the reef was clearly marked on the maps and called the accident "inexplicable." The ship caused about 20 yards of damage to the underwater rock formation and about 10 yards of damage to the coral reef.

The observatory paid a $200,000 fine for destroying the reef, which was located about 30 miles off the Yucatan peninsula. The ship left Mexican waters this week, after completing its five-week research mission to study the Chicxulub crater to learn more about the asteroid impact that might have led to the extinction of dinosaurs.

The team included scientists from Mexico's National Autonomous University, University of Texas Institute of Geophysics, and the Universities of Cambridge and London in the United Kingdom. Environmentalists opposed the ship's activities prior to the accident, saying that the seismic technology could cause harm to sea life, including whales that use sound waves to communicate.