Get reliable subsea integrity data with
Subsea Cathodic Protection Survey
Understanding your Cathodic Protection system’s performance provides a complete health assessment of your subsea assets. During a CP survey, we conduct a comprehensive inspection of the entire structure, delivering a full integrity picture that enables informed maintenance decisions and prevents costly failures.
Our CP survey gives you valuable insights into regulatory
compliance and 5-year inspection requirements
Intro
Cathodic Protection (CP) surveys are critical inspections that detect corrosion issues before they become costly failures. Our certified divers conduct thorough examinations of your underwater installations, identifying coating damage, measuring voltage levels to verify optimal protection, and documenting remaining anode mass. Uncontrolled corrosion leads to structural failure, expensive repairs, and production downtime. Regular CP surveys identify problems early, extend asset lifespan, and provide predictable maintenance budgets.
Typical illustration we provide together with the report to easily get an overview
Take this into consideration when ordering a CP survey
Cathodic Protection (CP) is the industry’s primary defense against this invisible threat. By applying a controlled electrical current or using sacrificial anodes, CP systems reverse the natural electrochemical process that causes steel to corrode. When functioning correctly, these systems can extend the lifespan of subsea structures from decades to generations, protecting everything from jacket legs and pipelines to mooring systems and wind turbine foundations.
However, CP systems are not “install and forget” solutions. Coating damage from vessel impacts, marine growth, or installation procedures creates vulnerabilities. Anodes deplete over time. Electrical connections fail. Environmental conditions change. Without regular monitoring through professional CP surveys, operators risk discovering corrosion damage only after structural integrity has been compromised—when repairs become exponentially more expensive and dangerous.
For offshore oil platforms, a single corroded support member can threaten entire production facilities. For offshore wind farms, turbine foundation failure jeopardizes renewable energy investments and grid stability. Regular CP surveys provide the early warning system that keeps these critical assets operating safely and economically, ensuring that the infrastructure powering our world remains robust beneath the surface.
FiGS®. Force Technology
Whether you’re operating jackets, maintaining subsea cable infrastructure, or managing offshore wind foundations, our surveys provide detailed documentation you need to make informed decisions about maintenance, repairs, and operational planning.Whether you’re operating jackets, maintaining subsea cable infrastructure.
Managing offshore wind foundations, our surveys provide detailed documentation you need to make informed decisions about maintenance, repairs, and operational planning.
Jens is our lead CP Specialist
As an Associate Professor in Material Science, Jens combines academic excellence with hands-on industry expertise. With 17 years specializing in cathodic protection systems, he is a steadfast resource who elevates the entire Beyonc team with his deep technical knowledge.
Jens was instrumental in developing FiGS® (Field gradient Sensor), the industry-standard tool for CP measurements, revolutionizing subsea inspection accuracy. His comprehensive understanding of corrosion mechanisms and protection strategies ensures thorough assessments and actionable recommendations that safeguard your critical assets.
DNV RP-B401: The Industry Standard for Cathodic Protection
DNV RP-B401 is the recognized recommended practice from Det Norske Veritas that establishes the framework for cathodic protection of underwater structures against corrosion. The standard defines requirements for design, installation, operation, and inspection of cathodic protection systems, and any professional CP Survey must be conducted in accordance with these guidelines.
Following DNV RP-B401 ensures correct measurement of protection potentials, proper identification of areas with insufficient protection, accurate assessment of anode consumption and remaining service life, and documentation that meets regulatory requirements. Operators who adhere to this standard can more confidently extend the lifespan of their assets and avoid unplanned shutdowns that can cost millions in lost production and emergency mobilization.
Jackets and Offshore Platforms
Jackets are complex steel structures with hundreds of nodes, tubular members, and connections, often extending from the seabed through the splash zone and up to the platform deck. A quality CP Survey on a jacket must cover representative measurement points at all depth levels because corrosion rates can vary significantly depending on depth, oxygen availability, and whether the steel is in the splash zone, continuously submerged, or buried in sediment.
Critical structural nodes receive particular attention because these are often the points of highest stress concentration and where any weakness could have the most serious consequences. The inspection must document the condition of sacrificial anodes, noting not just their remaining mass but also how evenly they’re being consumed and whether some areas of the structure are being preferentially protected while others are left vulnerable.
Identifying areas with local coating damage is also crucial because even small breaches in protective coatings can create sites of accelerated corrosion if the cathodic protection isn’t adequate to protect the exposed steel. Typically, a grid-based inspection plan is followed where the structure is divided into zones that are systematically inspected, ensuring that no area is overlooked and that coverage is consistent across multiple survey campaigns.
Oil Cables and Power Cables
Subsea cables often stretch for many kilometers, creating unique challenges for inspection. A comprehensive survey requires a route survey along the entire cable corridor, burial depth assessment with multibeam or sub-bottom profilers, CP measurements at regular intervals and at critical points like landfall areas and crossings with other cables or pipelines, and free span mapping to identify areas at risk of fatigue from vortex-induced vibration.
For power cables between offshore wind farms and shore, additional considerations come into play. Electromagnetic interference with the CP system can occur, potentially affecting the accuracy of measurements or the effectiveness of the protection itself. The effect of alternating current on cathodic protection, sometimes called AC corrosion, is a relatively newly recognized phenomenon that requires careful monitoring. The condition at cable crossings and protection structures also needs documentation because these are often points of increased mechanical stress and potential damage.
In shallow water environments, cables face particular risks from anchoring, fishing activities, and natural seabed movement. Storm events can expose cables that were previously buried, or shift sediment to create free spans where none existed before. Regular surveying allows operators to track these changes and take remedial action before a failure occurs.
Monopiles for Offshore Wind
Monopiles are large steel tubes, often several meters in diameter, that are driven deep into the seabed to support offshore wind turbines. The CP Survey for these structures must focus carefully on potential measurements in the splash zone, where corrosion rates are typically highest due to the combined effects of oxygen, salt spray, and mechanical action from waves.
Assessment of scour and the need for backfilling is critical because the design of both the structural support and the cathodic protection system assumes certain burial depths. If scour exposes more of the monopile than intended, both structural integrity and corrosion protection can be compromised. Inspection of bolted connections, the flanges that join the monopile to the transition piece, is also essential because these are complex geometries where crevice corrosion can occur even when the overall structure is well protected.
Verifying cathodic protection both above and below the mudline presents unique challenges because the corrosion environment changes dramatically at this boundary. Steel buried in anaerobic sediment corrodes much more slowly than steel exposed to oxygenated seawater, but the transition zone can be particularly vulnerable if not properly protected.
Since wind turbine foundations often have design lifetimes of 25-30 years, with potential for life extension beyond that, regular CP Surveys are critical to ensuring the structures achieve their expected service life and continue operating safely and economically throughout their operational period.