The AUV conducted a total of 19 science missions including combinations of straight line transects, open grids, and quadrats with full cover between the lines. The full cover quadrats were located in shallow (~30 m) and deep water (~48 m) to test the potential of the AUV to be used as a long-term monitoring tool in water depths beyond normal SCUBA diving limits. Further, the deep-water, full cover quadrat was re-sampled to demonstrate the repeatability of AUV-based surveys.Towed video and digital stills were collected and aided where the AUV was deployed. Test the potential of the AUV to be used as a long-term monitoring tool in water depths beyond normal SCUBA diving limits.

In support of future science missions, an engineering demonstration was conducted to show the ability of the nupiri muka AUV to be deployed and operated at an ice shelf. The AUV was deployed from Davis Station, Antarctica, to conduct underwater surveys in the vicinity of, and beneath, the Sørsdal ice shelf. The AUV conducted several surface transits from the station to the ice shelf, where dive missions at various depths were conducted. The primary mode of operation was the AUV tracking near the seafloor. In addition, a patch survey was conducted near the stations, where several sediment grabs were taken.

This project aimed to demonstrate long endurance autonomous exploration using multi-robot teams. The project culminated in a 10-day demonstration on the Cascadia margin (Hydrate Ridge) consisting of a Wave Glider tending and providing navigational aiding to a Seaglider using a one-way travel-time inverted ultrashort baseline system (OWTTIUSBL). The system represents a proof-of-concept for ship-less long-range exploration.

The objectives of the work in SE Queensland (Nov. 2011) was to revisit dive sites inside and outside of a green zone offshore of Moreton Island. There were a few issues associated with working on a small vessel and on the final day of operations the AUV was lost in part due to the vessel not having sufficient fuel to stay on station when the vehicle did not surface on the completion of its dive. An extensive search was conducted over the following three days using Coast Guard vessels and aerial search but the AUV was not located. Two weeks later the vehicle washed ashore some 100km to the North of the site where it was last seen. It had sustained relatively little damage but this incident highlights the vulnerability of the Facility to the loss of its one asset. An ARC LIEF proposal has been submitted to support the development of multiple, smaller AUVs to help maintain the Autonomous Underwater Vehicles (AUV) Facility observing program

SE Queensland – Moreton Island (Babcock): Dive sites were selected inside and outside of a green zone offshore of Moreton Island. A broad grid was completed at each site and three dense grids completed in each of the depth bands 15‐20m, 20‐25m and 25‐30m. There was insufficient ship time available to deploy at other sites in the region where kelp has been documented, including in deeper waters and further north. Sites for targeted dredging, sub-bottom profiling and AUV imaging were then selected for detailed study of particular features. All activities were undertaken during a 21-day cruise aboard the R/V Southern Surveyor, Australia's Marine National Facility operated by CSIRO. The study of these structures may yield insights regarding potential future sea level changes and their potential impact on sensitive reef areas such as the GBR.

Solitary Islands (Barrett, Jordan, Hayes): Dives in the Solitary Islands were focused on surveying reef habitats around the Solitary Island Marine Park. The surveys were conducted as part of a collaboration between the IMOS Autonomous Underwater Vehicles (AUV) Facility, the National Environment Research Program (NERP) Theme 1 - National monitoring, evaluation and reporting and NSW DPI Fisheries. Dives focused on a number of reefs in 20 m to 60 m of water depth and consisted of both dense 25 m x 25 m full photo quadrants designed to allow repeat surveys over years and broader surveys up to 2km in length to document habitat distributions over broader scales. Additional scientific operations carried out at these sites include multibeam bathymetry, towed video and Baited Remote Underwater Video Stations (BRUVS).

The purpose of this deployment is to collect water column variables to understand biological and physical processes to understand the dynamics and potential for the current Red Tide bloom on Florida's West Coast.

Cox Ledge, Spring 2021

This submission includes two peer-reviewed papers from researchers at North Carolina State University presenting the modeling and lab-scale experimentation of the dynamics and control of a tethered tidal ocean kite. Below are the abstracts of each file included in the submission. Alvarez ECC: Flight and Tether Dynamics This paper models the dynamics of a marine tethered energy harvesting system focusing on exploring the sensitivity of the kite dynamics to tether parameters. These systems repetitively reels a kite out at high tension, then reels it in at low tension, in order to harvest energy. The kite?s high lift-to-drag ratio makes it possible to maximize net energy output through periodic cross-current flight. Significant modeling efforts exist in the literature supporting such energy maximization. The goal of this paper is to address the need for a simple model capturing the interplay between the system?s kite and tether dynamics. The authors pursue this goal by coupling a partial differential equation (PDE) model of tether dynamics with a point mass model of translational kite motion. Siddiqui JDSMC: Lab-scale closed-loop model and validation This paper presents a study wherein we experimentally characterize the dynamics and control system of a lab-scale ocean kite, and then refine, validate, and extrapolate this model for use in a full-scale system. Ocean kite systems, which harvest tidal and ocean current resources through high-efficiency cross-current motion, enable energy extraction with an order of magnitude less material (and cost) than stationary systems with the same rated power output. However, an ocean kite represents a nascent technology that is characterized by relatively complex dynamics and requires sophisticated control algorithms. In order to characterize the dynamics and control of ocean kite systems rapidly, at a relatively low cost, the authors have developed a lab-scale, closed-loop prototyping environment for characterizing tethered systems, whereby 3D printed systems are tethered and flown in a water channel environment.

Gulf of Maine Winter 2023 Survey