Hull Cleaning Regulations by Country: Where, When, and How Ships Can Clean Their Hulls in 2026
The maritime industry is facing increasing pressure to improve fuel efficiency while preventing the spread of invasive aquatic species. As a result, biofouling management and underwater hull cleaning have become key compliance requirements for ship owners and operators worldwide.
While regular hull cleaning improves vessel performance and reduces fuel consumption, not every country permits in-water hull cleaning under the same conditions. Regulations vary depending on environmental policies, port authority requirements, and local biosecurity risks.
In this guide, explore the latest hull cleaning regulations in 2026, explain the International Maritime Organization (IMO) guidelines, and provide practical advice for ensuring your vessel remains compliant during global operations.
Why Hull Cleaning Regulations Matter
Marine organisms such as algae, barnacles, mussels, and slime naturally accumulate on submerged ship hulls. This process, known as biofouling, increases hydrodynamic drag, leading to:
- Higher fuel consumption
- Increased greenhouse gas emissions
- Reduced vessel performance
- Greater maintenance costs
- Risk of transporting invasive aquatic species between ecosystems
Because of these environmental concerns, many coastal nations have introduced stricter biofouling management requirements based on IMO guidance.
IMO Biofouling Guidelines
The International Maritime Organization (IMO) updated its 2023 Biofouling Guidelines (MEPC.378(80)), encouraging ship operators to implement proactive biofouling management to reduce invasive species transfer and improve vessel efficiency. The IMO is also working toward a more comprehensive global regulatory framework.
The guidelines recommend that vessels maintain:
- A Biofouling Management Plan (BFMP)
- A Biofouling Record Book (BFRB)
- Scheduled hull inspections
- Planned underwater cleaning
- Appropriate antifouling coatings
- Risk-based maintenance strategies
Although these guidelines are not universally mandatory on their own, many countries have adopted or incorporated them into national regulations.
Hull Cleaning Regulations by Country (2026 Overview)
- Singapore
Singapore supports effective biofouling management and follows IMO guidance while regulating underwater operations through the Maritime and Port Authority (MPA). Hull cleaning activities generally require proper approvals, environmental controls, and experienced service providers that comply with local port requirements.
Best Practice
- Schedule cleaning with an approved underwater service provider.
- Follow MPA operational and environmental requirements.
- Maintain accurate cleaning records.
- United Arab Emirates (UAE)
Major UAE ports, including Fujairah and Dubai, have established operational requirements for hull cleaning to ensure environmental protection and navigational safety.
Operators should:
- Obtain required port permissions before commencing work.
- Follow port-specific environmental procedures.
- Use qualified commercial diving contractors.
Port authorities may have different procedures depending on the location, so requirements should always be confirmed before arrival.
- Australia
Australia has some of the world’s strictest biosecurity regulations.
Authorities expect vessels entering Australian waters to demonstrate effective biofouling management. Ships with excessive marine growth may face inspections, operational restrictions, or cleaning requirements before entering certain ports.
- New Zealand
New Zealand requires arriving vessels to effectively manage biofouling risks under its biosecurity framework.
Operators are expected to:
- Maintain a Biofouling Management Plan
- Keep cleaning records
- Demonstrate proactive hull maintenance
Failure to comply may result in inspections, delays, or biosecurity actions.
- Brazil
Brazil introduced new biofouling regulations aligned with the IMO’s updated guidelines.
Requirements include:
- Vessel-specific Biofouling Management Plan
- Biofouling Record Book
- Risk-based maintenance
- Authorization for certain in-water cleaning activities
- Compliance with local biofouling assessment criteria before entering Brazilian waters
- Europe
Several European countries are strengthening biofouling management policies, with increasing emphasis on environmentally responsible in-water cleaning and documentation.
Operators should verify local port authority requirements before scheduling underwater cleaning because regulations may vary between ports and coastal states.
When Should Ships Schedule Hull Cleaning?
Rather than waiting for significant marine growth, ship operators should implement a preventive maintenance schedule based on:
- Trading routes
- Water temperature
- Vessel idle periods
- Dry dock intervals
- Fuel performance trends
- Underwater inspection reports
Routine underwater inspections help identify marine growth before it impacts fuel efficiency or regulatory compliance.
How to Stay Compliant During Underwater Hull Cleaning
Regardless of where your vessel operates, these best practices help reduce compliance risks:
Maintain a Biofouling Management Plan
Document inspection schedules, cleaning intervals, antifouling coatings, and maintenance procedures.
Keep Accurate Cleaning Records
Maintain detailed records of inspections, underwater cleaning activities, and maintenance history.
Follow Local Port Requirements
Always verify port authority requirements before scheduling underwater cleaning.
Use Qualified Service Providers
Professional commercial diving companies understand local regulations, environmental requirements, and safe underwater operations.
Conduct Regular Underwater Inspections
Routine inspections help detect biofouling early and support proactive maintenance planning.
Benefits of Regulatory Compliance
A well-managed biofouling program provides more than regulatory compliance.
It also delivers:
- Lower fuel consumption
- Reduced carbon emissions
- Improved vessel performance
- Longer coating life
- Lower maintenance costs
- Reduced operational downtime
- Improved fleet sustainability
Why Choose Nereus Subsea?
Nereus Subsea provides professional underwater hull cleaning, ship repair, and underwater inspection services across Singapore, the UAE, and worldwide.
Our experienced commercial diving teams help ship owners and fleet managers:
- Maintain compliance with local port requirements
- Reduce biofouling and fuel costs
- Improve vessel efficiency
- Support sustainable maritime operations
- Minimize downtime through safe, efficient underwater services
Whether your vessel requires scheduled maintenance or emergency underwater services, Nereus Subsea delivers reliable solutions backed by technical expertise and a commitment to safety.
Frequently Asked Questions
- Are hull cleaning regulations the same in every country?
No. Each country and port authority may have different requirements regarding underwater hull cleaning, environmental protection, and documentation.
- What is a Biofouling Management Plan (BFMP)?
A BFMP is a vessel-specific document outlining procedures for preventing and managing marine growth on the hull in accordance with IMO guidance.
- Can ships clean their hulls while afloat?
Yes, in many locations. However, in-water hull cleaning is often subject to local approvals, environmental safeguards, and port-specific regulations.
- Which countries have strict biofouling regulations?
Australia, New Zealand, Brazil, and several other jurisdictions have strengthened biofouling requirements, while many additional countries are aligning with the IMO’s guidance.
- Why is underwater hull cleaning important?
Regular underwater hull cleaning improves fuel efficiency, reduces greenhouse gas emissions, minimizes biofouling, extends coating life, and helps vessels comply with evolving international regulations.
As environmental regulations continue to evolve, biofouling management is becoming a core component of responsible vessel operations. While the IMO provides an international framework, individual countries and port authorities continue to introduce their own requirements for in-water hull cleaning, inspections, and documentation.
For ship owners and fleet managers, staying informed about where, when, and how hull cleaning is permitted is essential for avoiding operational delays, maintaining compliance, and improving fleet efficiency. Partnering with an experienced underwater service provider like Nereus Subsea ensures your vessels receive professional hull cleaning and inspection services that align with local requirements and global best practices.