The Nereus was a hybrid ROV/AUV built by the Deep Submergence Lab at WHOI to explore the deepest parts of the ocean. WHOI engineers incorporated a number of novel technologies into its design for use in remote operations, including an optical fiber tether for use in remote operations, ceramic flotation, and lithium-ion batteries. DeepSea Power and Light designed, manufactured, and supplied the ceramic flotation equipment for the project which can be seen on the inner sides of the vehicle enclosed in clear tubes. The ceramic flotation is a great example of a challenge we solved.
UPDATE: On May 10, 2014, the Nereus was confirmed lost in the Kermadec Trench. During its deployments, Nereus brought back to the surface specimens of animals previously unknown to science and seafloor sediment destined to help reveal the physical, chemical, and biological processes that shape the deep-ocean ecosystem and that make ocean trenches unlike almost any other part of the planet.