Your Mast Survived the Lightning Strike. Are You Sure?

A lightning strike is often viewed as an isolated event on a superyacht. If the mast is still standing, it can be tempting to assume the vessel has escaped serious damage. The reality is often very different.

A typical strike delivers around 30,000 amps at temperatures roughly five times the surface of the sun. On a modern sailing yacht with a carbon fibre mast, integrated electronics, and composite rigging, that energy has to go somewhere. RigPro regularly encounters vessels that appear structurally sound after a strike, only for specialist inspection to reveal significant hidden damage. The most important issues are usually the ones you cannot see.

 

 The Rising Risk

Lightning strikes whilst sailing  insurance claims are increasing, particularly across the Mediterranean. Modern yachts depend on interconnected electronic systems – navigation, communication, load monitoring, vessel management – and a single lightning strike can affect multiple systems simultaneously. Not all failures are immediately apparent. Some faults only emerge under load or during operation.

 

Some lightning strike damage is immediately obvious: burn marks at masthead fittings, destroyed antennas and sensors, melted or deformed hardware, visible arcing on rigging components, and failed electronics. These issues require attention, but they are typically only the starting point for a thorough assessment.

 

Lightning introduces immense electrical energy into the rig structure. Our research programme – one of the few controlled high-voltage laboratory testing programmes conducted on composite-masted rig structures anywhere in the world – has demonstrated that the mast itself carries the majority of strike current regardless of what conductor is fitted inside it. The consequences are frequently internal and invisible.

 

Carbon fibre structural damage:  Carbon fibre is approximately 1,000 times more resistive than aluminium. When strike current is forced through it, the energy concentrates in localised zones. The resin matrix between the fibres can vaporise explosively, causing internal delamination and structural weakening that is not visible from the outside. Our laboratory testing has shown exactly how and where this damage occurs – and critically, what it tells us about the strike event itself. Without specialist inspection by engineers who understand these damage mechanisms, these defects can remain undetected until a structural failure occurs under load.

 

Standing rigging:  Whether rod, wire, or synthetic, standing rigging can sustain arc damage at terminals, hidden weakening at end fittings, and localised damage that is not apparent during normal operation. Lightning current follows the path of least resistance through the rig, and the points where it transitions between materials are where the most significant damage occurs. Our field experience across multiple post-strike inspections and our laboratory testing programme inform exactly where to look and what the damage patterns mean. Where damage is confirmed or suspected, RigPro recommends detailed assessment and, depending on severity, replacement of affected components.

 

RigPro’s lightning inspection capability is built on controlled high-voltage laboratory research – conducted across two phases at specialist accredited facilities using full-scale spar structures under simulated strike conditions. This is the only program of its kind in the marine industry, and it directly informs how we assess struck vessels.

For significant strikes, we deploy specialist engineers who understand where current flows through a composite rig, what the resulting damage patterns mean structurally, and how to distinguish between damage requiring immediate remediation and damage that can be monitored. This is engineering analysis, not visual inspection.

We also maintain an active research programme evaluating lightning protection technologies. Our recommendations are based on evidence, not manufacturer claims.

 

The most expensive consequence of a lightning strike is rarely the initial repair bill. It is the hidden damage that goes unnoticed until a failure occurs under load – potentially offshore, potentially in conditions where a rig failure has serious consequences for crew safety.

If your yacht has experienced a lightning strike – or you suspect one may have occurred – a professional engineering assessment can provide the clarity needed to protect your crew, your vessel, and your sailing programme.

 

RigPro provides specialist lightning inspection, rig survey, maintenance, and repair services for sailing yachts and superyachts worldwide through our network of service centres and experienced engineers.