Broadening out the working footprint of a cabled seabed observatory using an interconnected surface buoy, and examining the potential to achieve similar utility from a stand-alone buoyed platform

This thesis describes the extensive study and analysis of a cabled seabed observatory connection and examination of the potential to achieve similar utility from a buoyed observatory system. The study then broadens out to investigate the potential to extend the utility afforded from a buoy to meet the demands of a challenging end user: The example chosen being the long-term real-time remote piloting of a resident Remotely Operated Vehicle (ROV). Current ocean observational systems have been identified as being inadequate by the Intergovernmental Oceanographic Commission (IOC) and the Global Ocean Observing System (GOOS), needing urgent improvement. In response, this research is driven by the requirement to extend observations over a broader footprint, using lower cost upcoming technologies to increase system capacity. This need for expansion led to a thorough examination of the current capabilities of ocean observation technologies, identifying areas where additional research is required. The findings highlight the divide between shore-connected cabled facilities and autonomous platforms in relation to energy availability, communications capabilities and spatial/temporal footprint. This necessitates a need for examination as to how this gap can be bridged. The design and build of a bespoke interconnector, linking the seabed Cabled End Equipment (CEE) at the Galway Bay Cabled Observatory to an adjacent surface buoy made it possible to examine the true differences in terms of data availability, energy and power delivery between the two platforms. Elements of the CEE utility were then extended (broadened out), including communication with adjacent infrastructure. This connection allowed analysis of data from the cable and the buoy to set the bar for what a standalone observatory would be required to equal. A study is then conducted to determine how lower-cost deep-field functionality could be realised, based on the analysis of the results from the cabled connection. A hybrid communications system (HF and Satellite) is proposed, in tandem with a triple hybrid (‘tribrid’) energy generation system (wind, wave and solar), and modelled outputs are presented using meteorological and oceanographic data from Galway Bay. The outputs were tested against the requirements of a challenging end user, i.e. teleoperation of a resident ROV with real time video relay, low latency requirements and requisite power. The work concludes that low latency remote presence ROV control is theoretically achievable on a remote platform, using energy generation, storage and communications system as described. Further in situ trials are required in future work to validate this across a range of operational conditions in the ocean.