On 15 March 2007, the second in a series of deep water expeditions to Mexico's La Pilita Cenote succeeded in further checking out the performance of the DEPTHX vehicle in preparation for an assault on the Zacaton Cenote. Zacaton is considered the world's deepest unexplored natural well expected to be deeper than 1000 meters. The combined research and operations team made multiple dives into La Pilita to refine navigation and life detection/collection systems. The team returned home and gave the "thumbs up" for the real test of DEPTHX in Zacaton in May. The project manager, Dr. Bill Stone said "DEPTHX continues to amaze us in its behavioral robustness just as we engineered it into the beast. As we planned, the two phase expeditionary risk reduction testing process has allowed us to better understand what we created, wring out problems, and determine how it will perform at Zacaton. This is a very exciting complex project in modern autonomous underwater operations. So far, this is a win-win for our team and NASA."