This report forms Deliverable 1.6 and details the work of Task 1.6 within WP1 of RealTide. It provides the description of the work carried out on the guidelines for the development of tidal turbines reliability databases. It covers the description of: 1) the requirements for the development of reliability databases recommended by industrial standards, 2) the process developed regarding the database utilization from pre-data collection to the reliability data reporting including data treatment, recording and processing; 3) the specifications for the construction of the database (structure, data tables, data relationship and queries…); 4) the reliability formulas to be used to calculate the readability and maintainability data; 5) the construction of a database demonstrator to simulate the database functionality with a set of dummy data for demonstrator testing; 6) indication of developments recommended for commercial database versions.