Exploring the deepest depths: Preliminary design of a novel light-tethered hybrid ROV for global science in extreme environments

This paper describes a new project to build an operational underwater vehicle that can perform scientific survey and sampling to the full depth of the ocean (11,000 meters). The vehicle, called a hybrid remotely operated vehicle (HROV), will operate in two different modes. For broad area survey, the vehicle will operate untethered as a autonomous underwater vehicle (AUV) capable of exploring and mapping the seafloor with sonars and cameras. After targets of interest have been found, the vehicle will be converted at-sea to become a remotely operated vehicle (ROV) that will enable close up imaging and sampling. The ROV configuration will incorporate 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. This paper outlines the scientific motivation for the project as well as the feasibility of our design concept. Analysis of the fiber optic cable shows our approach to be practical even with fairly extreme current profiles. An overall approach to the vehicle design is also presented, including options for pressure housings and buoyancy materials.