In the past few years, DNV has been involved in a variety of projects related to marine energy converters. All projects have been characterized for the handling of technical uncertainties due to the application of new technology or proven technology in different areas of application. A systematic approach based on the DNV RP-A203 Qualification of New Technology was applied combined with the Guidelines for Design and Operation of Wave Energy Converters (May 2005—work carried out by DNV under Commission of Carbon Trust as part of Marine Energy Challenge) to steer the third party activity, but, more importantly, to allow developers to systematically identify and deal with the risks in a rational manner with traceability of decisions throughout the development of the energy converter. From the very start of our engagement, it was clear that the handling of technical uncertainties was affected, not only by the technical barriers, but also by financial and time constraints. The establishment of the safety and functional targets to be achieved by the energy converter are to be based, not only on the safety and asset integrity aspects, but also on the financial∕business model. The experience of using the qualification process and the guidelines on these projects, achieving the right balance between the constraints, handling of uncertainties, financial targets, and safety and functional requirements, are briefly described in this paper as well as the future steps to be taken to improve the process and consolidate the experience so far. In this paper, the use of the DNV OSS-312 (Certification of Wave and Tidal Energy Converters) on the certification process of marine energy converters is also addressed.