ROVs vs. Divers: Key Factors for Selecting the Right Underwater Cleaning Service

As a fleet manager or operator of dry bulk and tanker vessels, maintaining hull cleanliness is crucial for fuel efficiency, operational performance, and regulatory compliance. Selecting the right hull cleaning service—whether utilizing Remotely Operated Vehicles (ROVs) or human divers—is a key decision. It can influence cost, safety, ship performance, and many other factors that ultimately impact your bottom line. To help you make an informed choice, we have put together a comprehensive guide on the key differences in ROVs vs. Human Divers for hull cleaning.

Introduction: ROVs vs. Divers in Underwater Hull Cleaning

Underwater Remotely Operated Vehicles (ROVs) are advanced, unmanned machines designed for tasks like hull cleaning, inspection, and maintenance. Controlled from the surface, ROVs use cameras, sensors, and cleaning tools to perform their work with precision and consistency. Unlike human divers, ROVs can operate continuously without breaks, even in challenging conditions like strong currents or low visibility.

While divers have been the traditional choice for hull cleaning for decades, ROVs have gained popularity since the 2000s as advancements in technology made them safer, faster, and more efficient for maritime operations. This innovation has created a new choice for fleet managers: human adaptability or machine consistency?

1. Safety: Prioritizing Risk Reduction

Safety is paramount in maritime operations. ROV-based cleaning services eliminate the inherent risks associated with human divers, such as decompression sickness, entanglement, and encounters with hazardous marine life. ROVs can operate in challenging conditions, including strong currents and low visibility, where diver safety would be compromised.

Human divers, while adaptable and capable of handling unexpected situations, face significant safety risks, especially in adverse environmental conditions. Utilizing ROVs mitigates these risks, ensuring safer hull cleaning operations.

2. Environmental Impact: Managing Biofouling Responsibly

Environmental regulations concerning biofouling and debris discharge are becoming increasingly stringent. ROV-based cleaning services often incorporate systems designed to capture biofouling debris, preventing harmful discharge into surrounding waters. This approach aligns with environmental compliance and reduces the risk of invasive species spread.

In contrast, diver-based services may lack integrated debris collection systems, potentially leading to unintentional environmental impacts. For operators focused on sustainability and compliance, ROV services typically offer better environmental safeguards.

However, keep in mind that ROV-based biofouling capture systems often require approval from the port authority before operating. Without the approval, the ROV will not be allowed to perform a cleaning despite what the technology may otherwise be capable of. Always ask your cleaning service provider to confirm that they have all relevant approvals from the port, terminal, or water body you plan to clean in.

4. Speed: Minimizing Vessel Downtime

Time is a crucial factor in maritime operations, as the cost of chartering a vessel often surpasses all other operational expenses. This makes speed and efficiency even more critical metrics than cost when evaluating performance.

ROV-based services excel at completing large-scale cleaning tasks quickly and efficiently, reducing vessel downtime. Their ability to operate continuously without breaks makes them an attractive option for fleet managers prioritizing operational speed. Most recently, Norwegian hull cleaning pioneer Ecosubsea launched its Ultra High Efficiency Hull Cleaning Service (UHEHCS) in Singapore, promising capesize vessel cleanings in just four hours.

Diver-based services, while effective for targeted cleaning, generally take longer for large-scale operations due to the need for rest periods and manual cleaning processes.

See how Western Bulk optimized vessel cleaning to cut downtime with CleanQuote: Western Bulk Case Study

5. Cleaning Quality: Human Precision vs. ROV Consistency

Both cleaning methods offer distinct advantages when it comes to quality and hull protection. Human divers excel in precision, adapting their techniques in real-time to effectively clean intricate areas like propeller shafts and intake grates. This level of control can also help divers avoid unnecessary damage to sensitive hull coatings, making them a strong choice for vessels with complex geometries or high-maintenance surfaces.

ROVs, on the other hand, provide unmatched consistency across large, flat surfaces. Equipped with advanced tools and operated by skilled technicians, modern ROVs can deliver uniform cleaning results while minimizing the risk of coating damage. Consistent pressure control and specialized cleaning mechanisms reduce the chances of over-cleaning or scraping, though the operator’s expertise and the equipment’s condition remain crucial to ensure safe and effective results.

Ultimately, when it comes to quality, the question of ROVs vs. Human Divers depends on the complexity of the task and the importance of protecting your hull coatings. For intricate cleaning needs, divers bring adaptability and precision, while ROVs excel at broad, consistent cleaning with less risk of fatigue-induced errors. Fleet managers should prioritize providers—whether using divers or ROVs—that demonstrate expertise in both delivering high-quality cleaning and preserving the integrity of hull coatings.

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7. Operating Conditions: ROVs Excel in Challenging Environments

ROVs are designed to thrive in challenging underwater conditions, such as strong currents, low visibility, and rough seas, where human divers face significant risks. Unlike divers, ROVs are unaffected by fatigue or sensory limitations, delivering consistent cleaning results even in adverse environments. For vessels operating in high-current ports, offshore zones, or murky waters, ROVs provide reliable cleaning without compromising safety.

Human divers, while adaptable, are constrained by environmental factors. Strong currents and poor visibility can slow operations, increase risks, and even force delays until conditions improve. These limitations make ROV-based cleaning a more dependable option for fleet managers prioritizing efficiency and safety in tough environments. With ROVs, vessel cleaning schedules stay on track regardless of the challenges below the surface.

Conclusion: Tailoring the Choice to Your Fleet’s Needs

Both ROV- and diver-based hull cleaning services have their advantages. For large vessels prioritizing safety, speed, and environmental compliance, ROV-based providers are an excellent option. For smaller vessels, targeted cleanings, or jobs requiring precision, diver-based providers may be more suitable.

A hybrid approach—leveraging ROV services for routine, large-scale cleaning and divers for specialized tasks such as niche cleanings—can offer the best balance of efficiency, quality, and adaptability. By aligning the service choice with your fleet’s specific requirements, you can maintain optimal vessel performance while minimizing costs and environmental impact.

Despite advantages in some areas, ROV services are also not yet available at large scale in every port. This means divers remains the standard in most ports and for most vessels.

No matter your stance on ROVs vs. Divers, you can explore CleanQuote’s services to find the perfect hull cleaning solution for your fleet among more than 100 vetted suppliers.