Arcus archives

Understanding the Impact of Stray Current on Yacht Rigging

Wednesday 28th May 2025

Stray current is a silent yet powerful force that can cause significant damage to stainless steel components in marine environments. Over the past three decades, we’ve witnessed firsthand how stray current has compromised yacht rigging systems, sometimes with devastating consequences. In one notable case, a yacht sailing from Sydney to Brisbane experienced severe contamination and wire failure shortly after re-rigging. Even after replacing the wire and fittings, the vessel lost its rig on its next journey from Brisbane to North Queensland. This is just one example of how stray current, when combined with stainless steel in a saline (saltwater) environment, can contribute to a phenomenon known as hydrogen embrittlement.

Misconceptions About Quality and Stray Current

One of the biggest misconceptions in the marine industry is the assumption that stray current issues are a result of poor-quality wire rope. At Arcus Wire Group, we exclusively supply market-leading hamma wire rope and hamma regatta, products that are recognised globally for their superior quality. Unlike low-cost, lower-quality Chinese products, hamma by KOS is manufactured in South Korea—widely regarded as the number one producer of G304, G316, and Duplex 2205 wire rope for decades. Meanwhile, hamma Regatta, manufactured in Thailand, consistently meets the highest industry standards, backed by ISO-certified quality audits. Stray current is a real phenomenon, and its effects are not due to low-quality materials but rather electrical imbalances within the marine environment.

What is Stray Current?

Stray current refers to unintended electrical current flow that often occurs due to poor grounding or corrosion within an electrical system. On yachts, stray current is typically introduced through:

New electrical installations or upgrades
Solar panel installations
Extended periods of shore power connection
Faulty wiring or grounding

Yachts with extensive electronic systems, new solar panels, or those that have recently undergone electrical work are at a higher risk of stray current issues.

Signs of Stray Current

Stray current can often be detected through the following signs:

Rapid Tea Staining: Early signs of corrosion, particularly in the form of tea staining, can indicate stray current. This discolouration is more prevalent in stainless steel exposed to saltwater.
Broken Wires: Rapid failure of wires, often a single broken wire in a 1×19 strand.
Unusual Deposits: White, chalky residues on stainless steel components, which are byproducts of electrochemical reactions.
Electrical Shocks or Anomalies: Mild shocks when touching metal parts or unexpected tripping of breakers may also indicate stray currents.

Evidence of Stray Current on Long Voyages

From our experience at Arcus Wire Group, we have observed that stray current damage is more prevalent after long voyages. Several of our clients have reported signs of tea staining, broken wires, and premature wire fatigue after extended periods at sea. This aligns with industry findings, where continuous electrical flow over long distances increases the likelihood of stray current corrosion.

One of our most significant cases involved a yacht re-rigged with hamma wire rope in Sydney. After a long journey up the eastern coast of Australia, the vessel experienced severe corrosion and structural failure, which upon inspection, was attributed to stray current exposure.

Hydrogen Embrittlement: The Hidden Threat

When stainless steel components are exposed to stray current in saltwater, the resulting electrochemical reaction produces hydrogen ions. These hydrogen ions can enter the metal structure, causing it to become brittle and more prone to cracking under stress. This process, known as hydrogen embrittlement, is particularly concerning for yacht rigging because it compromises the integrity of critical load-bearing components.

Although 316 stainless steel—commonly used in marine rigging—has a reputation for resistance to corrosion, it is not immune to hydrogen embrittlement, especially when stray current is present. In fact, the presence of chloride ions in saltwater accelerates the absorption of hydrogen, increasing the risk of metal fatigue and failure.

Factors Contributing to Hydrogen Embrittlement

Magnitude of Stray Current – Higher current levels generate more hydrogen ions, increasing the risk of embrittlement.
Mechanical Stress – Rigging components under tension are more susceptible to cracking once hydrogen has entered the metal structure.
Chemical Composition of Seawater – High concentrations of chloride ions expedite hydrogen absorption.
Temperature Variations – Embrittlement is most pronounced in moderate temperatures, typical of most sailing conditions.

How to Protect Your Rigging

To reduce the risk of stray current damage:

Regularly inspect electrical systems for signs of corrosion or faulty wiring.
Ensure proper grounding of all electronic equipment.
Limit long-term connections to shore power unless appropriate isolation transformers are installed.
Monitor and maintain solar panel installations to prevent electrical imbalances.

Setting the Standard: Industry Awareness

Hydrogen embrittlement and stray current are receiving growing attention within the marine industry. Leading industry bodies such as ABYC (American Boat and Yacht Council) and IMCI (International Marine Certification Institute) are actively setting guidelines to mitigate these risks through better electrical practices and material specifications. By understanding and managing stray current effectively, yacht owners can significantly extend the life of their rigging and improve safety at sea.

Understanding the technical risks of stray current is one thing—but seeing its impact in the real world is another. Over the coming months, Arcus Wire Group will publish a series of detailed case studies highlighting real-world incidents where stray current led to rigging failures.

🔗 Lisa Blair Case Study – Dismasting in the Southern Ocean

Lisa Blair’s solo circumnavigation of Antarctica came to a halt after her mast collapsed due to galvanic corrosion caused by stray current. With rigging supplied by Arcus and expert analysis from our technical team, this high-profile case illustrates just how dangerous stray current can be—even when premium materials are used.

Two more case studies, including a coastal cruiser with solar upgrades and a racing yacht with repeated failures post-refit, will be released soon.

Arcus Wire Group is committed to educating the yachting community about the risks of stray current and how to prevent costly and dangerous rigging failures. As more yachts are fitted with advanced electronics, understanding the hidden threats of stray current is more important than ever.

For further information on protecting your yacht rigging, call 1800 ARCUSW (1800 272 879) or email [email protected] to contact our technical team for expert advice.