Scope Overview

Offshore wind turbine foundations require routine subsea inspection to monitor structural condition and verify the performance of cathodic protection systems. Operating in harsh marine environments, these structures face coating degradation, anode depletion, scour, fatigue related damage and rapid marine growth, all of which can escalate risk and increase maintenance costs.

The client tasked Innovair with delivering a detailed CP survey and visual inspection campaign across multiple foundations to provide dependable integrity insight without disrupting ongoing offshore operations. The objective was to obtain accurate CP measurements, high quality visuals and a clear understanding of overall foundation condition.

The Challenge

Gaining reliable insight into subsea foundation condition presents several operational and environmental challenges, including:

• Strong tides and shallow turbulence affecting ROV stability and reducing coverage.

• CP stab probes offering only isolated point readings rather than whole system performance.

• Risk of increased cost, emissions and downtime when relying on dedicated vessels and long standalone campaigns.

The inspection required a robust ROV solution capable of stable operation in demanding conditions while integrating seamlessly with the clients wider offshore programme.

The Solution

Innovair deployed the VALOR digital class ROV equipped with a calibrated FiGS field gradient sensor and high resolution stereo imaging on a custom skid. This configuration enabled precise CP mapping and detailed GVI within a single, efficient campaign.

Key features included:

• Stable ROV performance in strong tides and shallow turbulence up to 1.5 metres per second, safely deployed via SOV crane and deck.

• Accurate field gradient assessment through an integrated FiGS sensor mounted on a custom engineered skid.

• Comprehensive visual coverage of anodes, coatings, cable entry points, boat landings and marine growth to ensure full foundation assessment.

The Results

• Full FiGS and GVI coverage across 11 foundations, with 26 dives completed over 7 efficient operational days

• Comprehensive reports and high quality video delivering a reliable baseline for ongoing integrity assessment.

Want more information?

Download the full case study to learn more about how Innovair’s combined FiGS and visual inspection campaign delivered dependable, high clarity insight into WTG foundation condition while operating efficiently from the in field SOV.