Seawater is one of the most aggressive environments for metallic structures, making corrosion a constant threat to ships, FPSOs, and offshore infrastructure. Without adequate protection, steel hulls, ballast tanks, rudders, and sea chests deteriorate rapidly; compromising performance, safety, and structural integrity.
To counter this, marine cathodic protection (CP) systems are widely deployed. Corrpro Europe provides both impressed current cathodic protection (ICCP) and sacrificial anode solutions engineered to meet the demands of harsh maritime environments.
How Marine Cathodic Protection Systems Work
Cathodic protection mitigates corrosion by making the hull surface the cathode of an electrochemical cell. In marine environments, two main CP methods are used:
Impressed Current Cathodic Protection (ICCP)
ICCP systems use inert anodes powered by a transformer rectifier (TR) to deliver a controlled current to the ship’s submerged surfaces. Corrpro’s Power Units and Hockway™ units, used in both standard marine and specialist offshore applications, supply reliable and adjustable protection across diverse hull geometries and vessel types.
ICCP is especially suited to:
- Naval vessels and larger commercial ships
- Offshore platforms and FPSOs
- Projects requiring automated control and remote monitoring
- Situations where weight and longevity are critical
Sacrificial Anode Systems
Sacrificial (galvanic) anodes made of aluminium or zinc alloys corrode preferentially, protecting the vessel’s steelwork. Corrpro Europe manufactures Aloline® and Zincoline® anodes at its UK foundry, supplying custom solutions for hulls, tanks, rudders, and internal systems. These systems are simple to install and require no external power, making them ideal for coastal vessels and vessels with limited power access.
Key Corrosion Risks in Marine Environments
Saltwater conductivity accelerates electrochemical corrosion. Marine vessels and offshore platforms are vulnerable in several critical areas:
- Hull – exposed continuously to seawater and marine organisms
- Ballast tanks – frequently subject to wet-dry cycles and internal corrosion
- Sea chests and cooling systems – complex geometries prone to under-deposit corrosion
- Rudders and shafts – moving parts exposed to galvanic coupling and flow-induced corrosion
Without CP, localised pitting or general corrosion can develop, leading to expensive dry-docking and steelwork replacement.
Importance of Monitoring and Reference Electrodes
A successful ICCP system depends on accurate feedback from reference cells, typically silver/silver chloride or zinc electrodes mounted on the hull. These sensors monitor hull potential and provide the control signal for current regulation. Corrpro Europe’s systems integrate robust monitoring capabilities to maintain optimal protection and prevent both under protection and over-polarisation, avoiding corrosion and coating damage.
For more advanced applications, remote monitoring and control (RMC) is available via Corrpro Europe’s bespoke Hockway TR units. These allow shipowners and operators to monitor CP performance in real time and adjust settings remotely, which are critical for FPSOs, naval vessels, and high-value assets where consistent protection is essential.
Choosing the Right System: Standard vs Bespoke Marine Power Units
Corrpro Europe offers two tiers of ICCP systems:
- Standard Marine Power Units – Cost-efficient, durable, and ideal for commercial vessels and shipyards where straightforward protection is required.
- Hockway™ TR Systems – Bespoke transformer rectifiers engineered for extreme environments and specialist applications such as defence, offshore, and RMC-enabled platforms.
This flexibility allows Corrpro Europe to provide optimised CP solutions tailored to the asset, location, and operating conditions.
Stock based Delivery of Spare Parts and CP Components
Corrpro Europe supports shipyards and offshore operators by delivering materials with short lead times and excellent quality. With a UK-based foundry and large stocks of anodes, cables, reference cells, and TR components, Corrpro Europe can fulfil urgent requests with minimal lead times. This capability is critical for dry-docking schedules, emergency repairs, and retrofits.
Several thousand vessels worldwide have been fitted with Corrpro CP and antifouling systems, demonstrating both reliability and global reach.
Ask The Engineer
Below are key questions answered by a technical specialist at Corrpro Europe.
How does cathodic protection prevent hull corrosion in seawater?
Cathodic protection polarizes the hull to a more negative potential, suppressing the electrochemical reactions that cause corrosion.
Can cathodic protection be used in combination with antifouling coatings?
Yes. Corrpro systems are fully complementary, and MGPS, antifouling, and CP systems can operate together without interference.
How often do anodes need to be replaced on ships?
Anodes are typically replaced during scheduled dry-docking intervals, usually every five years. However, systems can be designed for longer service life depending on vessel requirements.
What are the advantages of using remote monitoring with ICCP systems?
Remote monitoring allows corrosion protection specialists to assess system performance and adjust current output without the need for local expert intervention on the vessel.
How are transformer rectifiers adapted for marine environments?
Transformer rectifiers are generally installed in indoor spaces; however, Corrpro Europe (Hockway) can manufacture units specifically designed for harsh and extreme outdoor marine environments.
Dependable Protection at Sea Starts with Corrpro Europe
Corrpro Europe delivers precision-engineered cathodic protection systems backed by decades of marine experience. From standard sacrificial anode kits to bespoke ICCP systems powered by Hockway™ TR units, we provide full design, manufacturing, and after-sales support.
Whether outfitting new builds or retrofitting during dry-dock, Corrpro Europe offers spare part supply, expert consultancy, and reliable systems that extend the lifespan of maritime assets.
Speak to our team today to learn how we can support your vessel or offshore project.
