Home NI603 Current and tidal turbines This Guidance Note gives requirements applicable to fully submerged current and tidal turbines (CTT) installed on the seabed with a view at their assessment and certification. Reference Title Edition NI603 R01 Current and tidal turbines May 2015 check related documents: NI631 Certification scheme for marine renewable energy technologies NI605 Geotechnical and foundation design Check other Bureau Veritas rules and guidelines.