Biofouling Rules at IMO Could Reshape Ship Maintenance — BIMCO Seeks Industry Input

The IMO is working towards what could become the first legally binding global framework for ship biofouling management, with discussions potentially affecting how vessels are inspected, cleaned and maintained.

BIMCO is urging shipowners, operators and seafarers to share practical experience before the regulatory framework takes shape.

From guidelines to binding requirements

Biofouling — the accumulation of organisms such as algae, barnacles and other marine life on a vessel's underwater surfaces — is already an operational concern for shipping. It can increase hull resistance, raise fuel consumption and contribute to the transfer of invasive aquatic species between regions.

The IMO is now discussing measures that could turn biofouling management into a more formal and enforceable global requirement.

Proposals currently under consideration include mandatory biofouling assessments, defined thresholds for cleaning, deadlines for corrective action, certification requirements and enforcement mechanisms.

For ship operators, this could eventually mean that biofouling management becomes more closely integrated with routine vessel inspections, maintenance planning and port operations.

BIMCO wants operational evidence

BIMCO is asking the maritime industry to participate in its biofouling survey, arguing that IMO negotiations need more evidence about what can realistically be implemented onboard and ashore.

The organisation is seeking information on areas such as:

• Current inspection and biofouling management practices
• Hull cleaning and coating experience
• Availability of cleaning services in different regions
• Operational restrictions faced by crews
• Costs and practical challenges associated with cleaning
• Existing approaches to monitoring and managing biofouling

The objective is to give policymakers a clearer picture of the difference between what may be technically desirable and what can actually be delivered across a globally trading fleet.

Why implementation could be challenging

A biofouling requirement that works well for a vessel operating regularly between major ports may be considerably harder to implement for a ship trading in regions where underwater inspection and cleaning services are limited.

Timing could also become an important operational issue. If vessels are required to clean their hulls after crossing a particular threshold or within a specified period, owners and operators may need to coordinate cleaning with port calls, cargo schedules, drydock plans and availability of approved service providers.

For crews, additional inspection, documentation and reporting requirements could become part of normal vessel operations.

There is also the question of unintended consequences. For example, poorly planned cleaning operations could create environmental concerns of their own, while limited service availability could create difficulties for ships that need corrective action within a prescribed timeframe.

Industry experience could influence the final framework

BIMCO says previous industry surveys have helped demonstrate both the shipping sector's commitment to controlling biofouling and the practical difficulties involved.

The organisation is therefore encouraging participation from operators of both individual vessels and large fleets.

The information gathered could help provide IMO negotiators with real-world evidence on inspections, cleaning, coatings, service availability and operational constraints before detailed requirements are finalised.

For shipowners and operators, this is an important opportunity to make sure that future requirements reflect the realities of international shipping rather than being designed solely around theoretical compliance models.

Why this matters

• For shipowners and operators: New requirements could affect maintenance schedules, cleaning costs, documentation and vessel availability.
• For seafarers: Crews may face additional inspection, monitoring and record-keeping responsibilities related to hull condition and biofouling.
• For ports and service providers: Demand for compliant underwater inspection and cleaning capabilities could increase significantly if mandatory thresholds are introduced.
• For the wider industry: Practical feedback now could help determine whether future rules are consistently workable across different trading routes and regions.

The bottom line

The IMO's emerging biofouling framework could become a significant new layer of operational compliance for the global fleet. The industry's practical experience will be particularly important in determining how those requirements work in the real world.

For ship operators, this is not simply a regulatory discussion — the decisions being made now could influence everyday hull maintenance and port operations for years to come.