According to industry reports, a significant share of the global commercial fleet has entered an ageing phase, leaving shipowners to grapple with how to extend the service life of existing vessels. Corrosion protection is shifting from a routine drydocking item to a key factor in whole-life asset costs.
What Happened
Clarksons data from July 2025 showed that 38% of global fleet capacity was more than 15 years old, including 30% of bulk carrier capacity and 33% of containership capacity. This means a large number of vessels will continue trading for another decade or more, requiring longer protection for their steel structures.
DNV survey data identifies corrosion as the most common cause of hull findings. Inspections of bulk carriers and oil tankers show a significant increase in corrosion findings in water ballast and cargo tanks at the third renewal survey, peaking at the fourth, broadly when ships reach 15 and 20 years of age.
Amendments to the IMO Enhanced Survey Programme Code that entered into force in July 2024 mean certain tanks where protective coatings fall below a “good” condition can become subject to more frequent examination. Corrosion can cause local and general reductions in steel thickness, while pitting and grooving can contribute to cracking, holes and leakage, sometimes requiring steel renewal between scheduled surveys and bringing additional repair and off-hire costs.
Background
Shipping is investing heavily in next-generation vessels, fuels and propulsion technologies, but a large part of the existing fleet will still be trading well into the next decade. Tank tops, lower stools and other cargo hold structures on bulk carriers face abrasion and impact during cargo operations, while lashing bridges and working areas on containerships are similarly exposed to mechanical damage. Once the protective barrier is breached, the underlying steel is again exposed to the marine environment.
Industry views suggest coating selection should move beyond initial application cost. The cheapest system at the point of application is not necessarily the lowest-cost system over the remaining life of the structure. If coatings repeatedly require repair, or deterioration eventually results in steel renewal, the owner pays for that original decision several times over.
Impact on Shippers
An ageing fleet and rising corrosion maintenance needs could indirectly affect cross-border logistics schedules and costs. When vessels require unscheduled repairs or steel renewal due to corrosion, it can lead to unplanned off-hire, potentially affecting schedule reliability. Shippers may face berth adjustments or longer transit times.
On the cost side, increased owner spending on corrosion protection could eventually feed into freight rates. For Chinese exporters to the US, choosing services with stable schedules and younger vessels can help reduce cargo delay risks. Customs clearance itself is not directly affected, but schedule volatility can disrupt post-arrival container pickup and delivery arrangements.
Recommendations
Shippers are advised to monitor the age and schedule reliability of vessels on their chosen routes, build in buffer time by stocking up earlier during peak seasons, and stay in close contact with logistics providers for schedule changes. Adjusting ocean-parcel or ocean-truck delivery plans when necessary can help avoid delays caused by unscheduled vessel repairs.