14/06/2026
EXPERT STORY n•11 – The Coating That Covered the Problem
At first glance, the cargo hold looked impeccable.
Fresh coating.
Uniform color.
No visible corrosion.
No obvious structural concerns.
To most observers, it was a well-maintained vessel.
But in marine surveying, appearances can be misleading.
During our inspection, we noticed subtle differences in the coating texture around several longitudinal stiffeners. Nothing alarming to the naked eye, but enough to justify a more detailed investigation.
We decided to perform Ultrasonic Thickness Measurements (UTM) across multiple locations.
The results completely changed the picture.
Beneath the new coating, several structural members showed significant steel wastage, with thickness reductions approaching and, in some locations, exceeding the allowable limits.
The coating had not preserved the steel.
It had simply hidden its condition.
Further examination revealed that the surface preparation before painting had been insufficient, allowing corrosion to continue beneath the protective system. In some critical areas, the remaining steel thickness had already compromised the original design margin.
Had this vessel continued trading without detection, progressive loading cycles could have accelerated cracking, deformation, or costly structural repairs during the next special survey.
Our recommendations were immediate:
✔ Full steel renewal in affected areas
✔ Removal of compromised coating and complete surface preparation
✔ Renewal of the protective coating system in accordance with manufacturer specifications
✔ Follow-up ultrasonic mapping after repairs to establish a new structural baseline
✔ Inclusion of these locations in future risk-based inspection programs
The owner was surprised.
“The hold looked brand new.”
And that’s exactly the lesson.
A fresh coat of paint is not proof of structural integrity.
The true condition of a vessel lies beneath the surface.
As surveyors, our responsibility is not to inspect what everyone can see.
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