As part of the Energy Cooperation between the North Seas Countries to facilitate the further environment friendly, sustainable and effective deployment of offshore renewable energy, this report provides an overview on the site investigation procedures that are applied. The differences and similarities of the procedures are outlined with special consideration of regulatory and technical aspects as well as relevant site conditions. As a result, the countries pooled according the quality and scale of the applied procedures and recommendations are given on how to achieve the most uniform and economical approach possible for the site investigation. Furthermore, suggestions for the future steps are derived.