The implementation of ocean current energy devices in several of the major global currents, such as the Gulf Stream and the Kuroshio Current, require specialized remotely operated vehicles for a wide range of tasks. Given the large water velocities, up to 3 m/s, and resulting vehicle and cable drag forces, the vehicle must be able to penetrate these flows while minimizing trail back from the target location. Tasks such as inspection, recovery, and basic intervention is required, particularly for the complex tasks of device interconnection and component recovery. Regulatory tasks are also required, given the need to recover previously ‘expendable’ items such as current meter anchors and other ‘below the release’ mooring components.
A vehicle concept is proposed, based upon previous designs used by the author to work in the Florida Current off South Florida. The deadweight, high lift capacity design incorporates the many benefits of modern electronics, while comparisons between 20th century technologies and procedures are highlighted with the proposed vehicle. Additional requirements, such as a suitable DP support vessel and deck equipment, are described, which in many instances utilize typical offshore tools in atypical applications. This approach also has relevance to other aspects of ocean energy, such as tidal and wave, when the situation may not have the luxury of waiting until slack tide or calm seas for a standard intervention.
