A robotic submarine is undergoing final preparations to dive to the deepest-known part of the oceans. If successful, Nereus will be the first autonomous vehicle to visit the 11,000m (36,089ft) Challenger Deep in the Pacific Ocean. Only two other vehicles have ever visited the spot before, both of them human operated. The $5m submarine will make the attempt in late May or early June after a series of increasingly deep dives. “ From 6,500m to 11,000m metres Nereus has the field pretty much to itself ” Ian Rouse National Oceanography Centre "Instead of jumping directly into the deep end of...