Few methods presently exist for routine benthic survey and sampling operations under permanent moving ice in high latitudes. Many benthic survey and sampling techniques commonly employed for blue-water oceanography are unsuitable for operations in ice covered seas due to the constrined maneuverability inherent in icebreaker operations. Over-theside deployments with lowered instruments prohibit ice-breaking and constrain the ship to the wind-driven motion of the ice. We propose that hybrid remotely operated vehicles (HROVs) with light data-only tethers could provide significantly enhanced under-ice scientific access to the world's high-latitude oceans. This paper identifies operational obstacles to benthic survey and sampling operations posed by permanent moving ice cover and proposes solutions to these obstacles.

This paper reports the results of sea trials of the Nereus hybrid underwater robotic vehicle (HROV) conducted in May and June 2009 in the Challenger Deep of the Mariana Trench, where the vehicle successfully performed scientific observation and sampling operations at hadal depths of 10,903 m. The Nereus underwater vehicle is designed to perform scientific survey and sampling to the full depth of the ocean significantly deeper than the depth capability of all other present-day operational vehicles. For comparison, the second deepest underwater vehicle currently operational worldwide can dive to 7,000 m maximum depth. Nereus operates in two different modes. For broad-area survey, the vehicle can operate untethered as an autonomous underwater vehicle (AUV) capable of exploring and mapping the sea floor with sonars and cameras. Nereus can be converted at sea to become a remotely operated vehicle (ROV) to enable close-up imaging and sampling. The ROV configuration incorporates a lightweight fiber-optic tether for high-bandwidth, real-time video and data telemetry to the surface enabling high-quality teleoperation. A manipulator, lightweight hydraulic power unit, and sampling instruments are added to provide sampling capabilities. This paper reports a brief overview of the Nereus vehicle design, and reviews the initial results of the eight dives conducted on this expedition, including two dives to more than 10,900 m depth. The Nereus vehicle is designed to render all parts of the Earth's seafloor reachable and the sea trials of its full-ocean depth capability in May and June 2009 were successful.

This paper reports an overview of the new Nereus hybrid underwater vehicle and summarizes the vehicle's performance during its first sea trials in November 2007. Nereus is a novel operational underwater vehicle designed to perform scientific survey and sampling to the full depth of the ocean of 11,000 meters - almost twice the depth of any present-day operational vehicle. Nereus operates in two different modes. For broad area survey, the vehicle can operate untethered as an autonomous underwater vehicle (AUV) capable of exploring and mapping the sea floor with sonars and cameras. For close up imaging and sampling, Nereus can be converted at sea to operate as a tethered remotely operated vehicle (ROV). This paper reports the overall vehicle design and design elements including ceramic pressure housings and flotation spheres; manipulator and sampling system; light fiber optic tether; lighting and imaging; power and propulsion; navigation; vehicle dynamics and control; and acoustic communications.

The Hybrid Remotely Operated Vehicle (HROV) Nereus, developed by the Woods Hole Oceanographic Institution (WHOI) with the support of the Space and Naval Warfare Systems Center San Diego (SSC San Diego) and the Johns Hopkins University, is intended to provide a new level of access for deep oceanographic research to a maximum depth of 11,000 meters. Nereus operates in two different modes. The vehicle can operate untethered as an autonomous underwater vehicle (AUV) for broad area survey, capable of exploring and mapping the seafloor with sonars, cameras, and other on-board sensors. Nereus can be converted at sea to become a remotely operated vehicle (ROV) to enable close up imaging and sampling. The ROV configuration incorporates a lightweight fiber optic tether to the surface for high bandwidth real-time video and data telemetry to the surface to enable high-quality teleoperation, additional cameras and lights, a manipulator arm, and sampling gear. Development of the fiber tether system was supported by both simulation and extensive field testing over a three year period. These tests demonstrated that an unprotected optical fiber could survive in the water column for greater than 24 hours and be effectively used as a high bandwidth data link by a remotely-operated, self-powered vehicle. Based on the data from the fiber trials, a robust tether deployment system was designed. The tether deployment system was integrated with the vehicle and demonstrated during field trials; in November 2007.

The Hybrid Remotely Operated Vehicle (HROV), being designed and built by Woods Hole Oceanographic Institution (WHOI) with the support of the Space and Naval Warfare Systems Center San Diego (SSC San Diego), will provide a new level of accessibility for deep ocean research. HROV will be primarily an autonomous vehicle but will be reconfigurable to a teleoperated system by the installation of a fiber optic data link and a manipulator based work system. Development of the fiber optic link has been supported by both simulation and a series of field tests over the past 3 years. The November 2004 tests consisted of deploying two different types of fiber optic cable from an Oceanographic elevator deployed from a ship to 2000 m depth. Data collected from this test demonstrated the feasibility of using both the Fiber Optic Microcable (FOMC) and plain buffered optical fiber as a tether for the HROV. The December 2005 tests demonstrated the utility of the buffered optical fiber operating on an underwater vehicle using the WHOI ABE vehicle as a substitute for the future HROV. Five dives were made to 2000 m with real-time communication from the vehicle to the surface via the fiber. The May 2006 tests focused on the employment of a cable depressor and deployment system. Using a deep elevator as a substitute for HROV, the fiber was deployed from both the depressor and the elevator to a depth of 4200 m. Over the course of 4 deployments, over 16 km of fiber was deployed, operating for a total of 33 hours, demonstrating the feasibility of the planned approach