One of the key developments of the marine energy industry in the UK is the demonstration of near commercial scale devices in real sea conditions and the collection of performance and environmental data to inform permitting and licensing processes.The ETI’s ReDAPT (Reliable Data Acquisition Platform for Tidal) project saw an innovative 1MW buoyant tidal generator installed at the European Marine Energy Centre (EMEC) in Orkney in January 2013.The project demonstrated the performance of the tidal generator in different operational conditions, aiming to increase public and industry confidence in tidal turbine technologies by providing a wide range of environmental impact and performance information, as well as demonstrating a new, reliable turbine designThis standard provides principles, technical requirements and guidance for the design, construction and in-service inspection of Horizontal Axis Tidal Turbine (HATT) and it is the basis for its certification.The specific certification requirements and respective deliverables for HATT are in line with the overall certification principles and procedures defined in DNV-OSS-312 Certification of Tidal and Wave Energy Converters