ROV LATIS is a next generation smart ROV with multiple modes of operation: Surface-Tow Mode, Surface-Thrusted Mode, ROV Operation Mode & ROV Submerged Tow in Strong Currents Mode. It is designed as a prototype platform to demonstrate system validity & operability and to prove new technologies developed in the Mobile and Marine Robotics Research Centre. Research outcomes are applicable to the growing international off-shore oil and gas sector, and also for future deployment, monitoring, and maintenance of ocean energy devices (in particular - wave energy converters and tidal turbines). System validation and technology demonstration was performed through a series of test trials with different support vessels off the west coast of Ireland. Selected results of the most recent field trials are presented in this paper.