This paper reports the development and at-sea deployment of a set of algorithms that have enabled the autonomous underwater vehicle ABE to conduct near-bottom surveys in the deep sea. Algorithms for long baseline acoustic positioning, terrain-following, and automated nested surveys are reported.

We present the design and at-sea results from a hybrid marine robot called Mesobot that can actively track midwater phenomena.

The 2012 submarine eruption of Havre volcano in the Kermadec arc, New Zealand, is the largest deep-ocean eruption in history and one of very few recorded submarine eruptions involving rhyolite magma. It was recognized from a gigantic 400-km² pumice raft seen in satellite imagery, but the complexity of this event was concealed beneath the sea surface. Mapping, observations, and sampling by submersibles have provided an exceptionally high fidelity record of the seafloor products, which included lava sourced from 14 vents at water depths of 900 to 1220 m, and fragmental deposits including giant pumice clasts up to 9 m in diameter. Most (>75%) of the total erupted volume was partitioned into the pumice raft and transported far from the volcano. The geological record on submarine volcanic edifices in volcanic arcs does not faithfully archive eruption size or magma production.

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.