Navigating Cleaner Seas: The Role of EGCS Systems on Commercial Vessels

In an era where the shipping industry is under increasing pressure to reduce its environmental footprint, key technologies like Exhaust Gas Cleaning Systems (EGCS) —commonly known as “Scrubbers”—are making waves.

These systems enable commercial vessels to comply with stringent international regulations such as the International Maritime Organization’s 2020 Sulphur Cap Mandate, which set the global limit of 0.50% m/m and a lower limit of 0.10% in Emission Control Areas (ECAs). Meaning the adoption of EGCS allow vessels to continue using heavy or high-sulphur fuel oil for cost-effective operations, while staying compliant.

But what exactly are they, how do they work, and are they the silver bullet for cleaner international shipping?

As a leading commercial diving company, we understand the importance of proper maintenance and inspection of these systems to ensure safety and efficiency.

Let’s dive in.

What Are EGCS Systems?

Exhaust Gas Cleaning Systems are helpful devices installed on ships to remove Sulphur Oxides (SOx) from exhaust gases produced by engines or boilers. Think of them as the shipping industry’s friendly version of a car’s catalytic converter, only much larger to fit container ships, tankers, and bulk carriers.

Thanks to these systems, vessels can meet international sulphur emission limits without having to switch to low-sulphur fuels, which are much more expensive.

The adoption of EGCS has surged in recent years, with thousands of vessels now equipped with them. As of 2025, they’re a key tool in the industry’s toolkit for reducing air pollution caused by shipping, which accounts for about 3% of global CO2 emissions and significant SOx output.

How Do EGCS Work?

At their core, EGCS “scrub” exhaust gases by passing them through a cleaning process before release into the atmosphere. There are three main types:

• Open-Loop Systems: These use seawater as the scrubbing medium. The seawater absorbs SOx, turning acidic, and is then discharged back into the ocean after treatment. It’s simple and cost-effective, and the most common type, making up 80% of global installations.
• Closed-Loop Systems: Here, a freshwater or alkaline solution circulates in a loop to clean the gases. The used water is treated onboard, with minimal discharge. This makes them more environmentally friendly in sensitive areas but requires more onboard storage and chemicals like sodium hydroxide, which drive up the operating costs.
• Hybrid Systems: The best of both worlds, these can switch between open and closed modes depending on location and regulations. They’re increasingly popular for vessels operating in varied waters, from open oceans to restricted ports.

Installation of either type can be conducted during the initial ship build, or can be done by retrofitting the ship’s exhaust stack with scrubber towers, pumps, and monitoring equipment.

Benefits for Ship Owners and Operators

• Cost Savings: The EGCS manufacturing and installation process can cost millions of dollars per vessel, but pays off through fuel savings. By sticking with heavy, high sulphur fuel, operators can save hundreds of thousands in fuel costs annually per ship, making payback periods for scrubber installations around 1-3 years only – not a bad investment!
• Regulatory Compliance & Flexibility: They ensure vessels meet IMO’s sulphur limits without a full switch to expensive fuels, avoiding penalties and operational disruptions. Hybrid systems allow seamless operation in Emission Control Areas (ECAs) like the Baltic Sea or North American coasts, where even stricter 0.1% sulphur limits apply.

Controversies and Challenges

Not all is smooth sailing!

EGCS, especially open-loop ones, have sparked debate over their ocean impact. Critics argue that transferring pollution from air to water isn’t a true solution—discharged waters can harm marine life by acidifying local waters and, introducing toxins. Some territories, regions and ports have even already banned the use of open-loop systems, citing the potential risk to local ecosystems.

However, closed-loop systems also discharge pollution into the sea – although much less than an open-loop system – the system still needs to “bleed off” from time to time, and such bleed off is likely to contain heavy metals with high acidity. Additionally, the closed-loop systems require the use of industrial chemicals, which generate internal sludge and residues that must be collected, stored and, disposed of properly. This again just shifts the pollution problem from the air to somewhere else, while also making monitoring operating, logistics, and planning even more challenging.

Ironically, EGCS systems increase overall engine loads due to the additional power needed to run the various pumps, fans, and treatment units involved in the EGCS system, which in turn leads to higher fuel consumption and emissions.

Different styles of EGCS discharges

Maintenance is another hurdle!

Because the wash water discharged from the EGCS systems is high in sulphur and chlorides and especially acidic, all its internal components are highly susceptible to incurring material degradation, namely in the form of scaling and, corrosion and, fouling.

This means the systems require frequent inspections, constant monitoring and, regular maintenance, to prevent failures, which can lead to safety issues and non-compliance fines.

Maintenance may include changing sensors in the continuous monitoring system, replacing valves, pumps and, fans, general cleaning and, keeping the system compliant with the latest software updates.

Different problems found during underwater inspections

Marine Growth Blockage

Crack in Internal Weld Seam

Role of Commercial Divers with EGCS

The most basic form of planned maintenance on EGCS systems is the underwater inspection. Since EGCS typically draws seawater from the sea chests intakes, it’s safe to say that a diver’s general underwater inspection on any vessel would adequately cover the EGCS subsea components, which consist of both intake (in the sea chests) and discharge(s). These inspections could help identify any gross damages or system blockages (marine growth or other debris).

A detailed/close examination of the EGCS could reveal any underlying issues with the weld seams, paint coating, and depending on the configuration, make an analysis of its internal condition. Divers can also carry out cleaning of the required areas or conduct underwater blanking/plugging to help facilitate internal operations.

Divers can also provide support for EGCS retrofit installations while vessels are afloat by carrying out underwater burning of hull penetrations, installing cofferdams and, performing underwater welding.

Blanking EGCS discharge

The Future of EGCS in Shipping

EGCS systems are pivotal in helping commercial vessels balance regulatory compliance, operational cost-efficiency, and environmental responsibility. Whether it’s an open-loop system for simplicity and cost, a closed-loop for environmental control, or a hybrid for adaptability, the right choice depends on vessel type, trade routes, and local regulations.

Looking ahead, EGCS will likely evolve alongside broader decarbonization efforts. The IMO’s push for net-zero emissions by 2050 means scrubbers might integrate with carbon capture technology or alternative fuels like LNG, etc.

Innovations in zero-discharge closed-loop systems could address water pollution concerns. As regulations tighten—think upcoming bans in sensitive areas like the Arctic—hybrid and advanced scrubbers will become standard.

However, the long-term shift might be toward truly green fuels, potentially rendering EGCS a transitional technology. For now, they’re bridging the gap, helping the industry sail toward sustainability. While not without flaws, they’ve cleaned up ship exhaust significantly. If you’re in the maritime sector, consider the trade-offs: short-term savings versus long-term eco-impact.

What do you think—scrubbers: Saviour or Stopgap?

Why Debris Is a Serious Threat to Commercial Shipping

The global commercial shipping industry is the lifeblood of international trade, transporting over 80% of goods traded globally. But as this industry grows, so do the challenges it faces — and one of the most overlooked yet increasingly dangerous threats is marine debris.

When we think of marine debris, things like plastic bottles and general discarded trash may come to mind – all of which are usually caused by negligent waste management practices.

However, debris in the form of ice, logs, shipping containers, fishing nets, broken buoys, etc. is usually not due to an intentional action, but rather by forces of nature or disastrous accidents.  Whichever the case may be, all debris in our oceans poses serious risks to ships, crews, and the environment.

Here’s why debris is a major concern for commercial shipping — and why it deserves more attention.

Damage to Vessels

Floating debris can cause significant physical damage to commercial vessels, especially when traveling at high speeds or navigating narrow or congested waterways. For example:

• Mechanical damages and entanglement: Ropes, nets, and plastic bags can get entangled in turning and steering gears, reducing maneuverability or potentially disabling the ship. Collisions with large debris, such as partially submerged logs and ice or abandoned containers, can dent propellers or puncture hulls — a serious safety hazard.
• Engine failures: Ingesting debris through seawater intake systems can clog filters, overheating engines, or damage internal systems.

These incidents can lead to expensive repairs, voyage delays, and — in worst-case scenarios — total vessel failure.

Navigation Hazards

Debris poses navigational challenges, particularly in busy ports, coastal areas, or straits.

With thousands of merchant ships navigating global waters, even a single piece of large debris can cause disruptions:

• False radar targets: Floating containers or debris masses can appear as ships or obstacles on radar, confusing navigation systems and increasing the risk of collision.
• Blocked routes: Accumulations of debris can make certain routes unnavigable, forcing ships to reroute and use more fuel.
• Delayed port entry: Debris near ports can slow down operations, especially during docking or loading/unloading procedures.

 

Economic Costs

The consequences of debris-related incidents aren’t just physical — they hit companies’ bottom lines:

• Maintenance and repair: Even minor damage from debris means unplanned dry-docking or equipment replacement.
• Downtime: Time lost due to detours, repairs, or slower speeds directly affects schedules and delivery deadlines.
• Increased insurance premiums: A vessel known to be operating in high-risk waters may face higher premiums due to potential damage from debris.

Combined, these costs can run into the millions — especially for large shipping companies operating globally.

Crew Safety and Working Conditions

Debris isn’t just a threat to ships — it endangers lives. Crew members may have to perform hazardous repairs at sea, or operate in unsafe conditions if engines or navigation systems are compromised.

Sudden stops or erratic steering to avoid debris can lead to onboard injuries, especially in rough seas. The psychological stress of working in unpredictable and dangerous environments can also impact crew morale and performance.

Environmental and Reputational Impact

A ship damaged by debris may accidentally spill fuel or cargo, compounding the environmental impact. When such events occur, shipping companies not only face regulatory fines, but also reputational damage — which can hurt business and stakeholder trust.

Moreover, some vessels may unintentionally contribute to the problem by losing cargo or discarding waste at sea, creating a negative feedback loop that harms the industry as a whole.

What Can Be Done?

Addressing the debris issue requires coordinated global efforts:

• Stricter waste management policies at sea and in ports. Operate within full compliance with international protocols, eg. MARPOL.
• Making changes for an environmentally friendly culture this starts at a local level, embracing positive changes through education, training and, disciplinary actions.
• Investment in ocean-cleaning technologies and debris monitoring systems.
• Better ship design and practices to prevent accidental cargo loss. Ensure cargo containers are correctly lashed using industry-standard equipment and procedures.
• Frequent inspections and maintenance by conducting underwater inspections for identifying and correcting potential hazards caused by debris.
• Collaboration with governments and NGOs to protect trade routes and marine ecosystems.
• Carry out debris removal campaigns to clean-up seabeds, buoys and, piers at busy commercial harbours and shipping routes. Commercial divers can also locate and salvage sunken items and debris that fall overboard.

Marine Debris in Thailand

Zooming in on Thailand specifically, it can be estimated that ~80% of debris found in Thailand’s waterways is directly caused by urban run-off  from cities and towns.

This may be significantly more around the tourist hotspots like Phuket, Koh Samui and, Pattaya.

As a local diving company, Thai Subsea Services has unfortunately witnessed its fair share of debris in Thailand’s oceans.

“When servicing commercial vessels throughout the country, there is rarely a vessel that has not been impacted debris one way or another,” said a company representative. “From fishing nets around shafts and thrusters, to plastic rubbish clogging sea chests, we see more and more debris almost daily.

These vessel don’t stand a chance, and some are in pretty rough shape or inoperational by the time we arrive.”

While local companies like Thai Subsea play their part in assisting with debris destruction, the Thai is government making positive efforts to mitigate the effects causing marine debris, including rolling out “Thailand’s Roadmap on Plastic Waste Management (2018–2030)”: Phasing out single-use plastics and Marine Debris Management Action Plan (2019): Focus on reducing debris from fisheries, tourism, and shipping.

Additionally, local NGOs and beach clean-up groups like Trash Hero, Green Fins, and Ocean Conservancy continue to do their part to help minimize the impact.

Impacted by Marine Debris?

Should a suspected incident of marine debris occur to your vessel or asset, call  Thai Subsea Services (TSS).

The Thailand-based commercial diving company services all anchorages and ports nationwide and has dive teams to dispatch 24/7.  After frequent encounters with vessels falling victim to debris, they are an expert in this field.

Among routine operations, such as debris clearing of thrusters, rudders and, rope guards,

TSS can provide bespoke repair solutions for all types of damages caused by marine debris, including propeller blade repairs, hull insert plates and, more.

Propeller Repairs

 

Why Do Ships Break? Understanding the Factors Behind Ship Failures

Ships are incredible feats of engineering, designed to withstand the harshest conditions of the sea. Yet, despite their massive size, advanced materials, and cutting-edge technology, ships still break or fail.

While the title of this blog may seem broad or blatantly obvious, it is worthwhile discussing the causes of these failures, which can range from human error to natural forces, mechanical breakdowns, structural weaknesses, and how proper maintenance and subsea intervention can help to mitigate them.

In this blog post, we’ll explore some of the primary reasons why ships break, and what can be done to prevent these catastrophic events.

1. Structural Stress and Fatigue

One of the most common reasons for ships breaking is the stress they experience while navigating the open seas. The constant motion of the vessel—especially when moving through rough waters—causes stress on the ship’s structure. This is particularly true for large ships like tankers, container ships, and cruise liners, which are subject to immense forces.

Over time, repeated flexing and bending of the ship’s hull can lead to metal fatigue, where small cracks or fractures develop in the hull.

These cracks can grow over time and eventually cause the ship to break apart, especially if the ship is subjected to unexpected stresses, like an intense storm or collision.

Preventive Measures: Regular maintenance, inspections are essential at spotting small problems before becoming catastrophic failures.  Also, the use of more fatigue-resistant materials (like advanced alloys and composites during the construction phase) can help reduce the risk of structural failure. Ships are often designed with redundancies, meaning multiple safety measures are in place to prevent catastrophic breakdowns.

2. Corrosion

Saltwater is one of the most corrosive environments on Earth, and ships are continuously exposed to it. Over time, the steel hull of a ship and its appendages (also steel) will corrode, weakening their structure and compromise their intended functions.
This corrosion often occurs below the waterline where it is harder to detect and repair. Without proper maintenance, this can lead to the thinning or pitting of the hull, making it more vulnerable to punctures or cracks.

Preventive Measures: While corrosion inspections can be routinely carried out by a vessel’s crew. Regular underwater inspections should also be conducted to look for signs of damage or loss of coverage to the vessel’s anti-fouling and coatings below the waterline.

These inspections will highlight any areas exposed steel or those areas susceptible to corrosion. Any corrosion that is found can be tested via thickness and pitting gauges and a scheduled inspection program can be put in place to monitor corrosion progression. For areas that are found extremely corroded, major repair intervention may be required to completely replace the failed hull plating.

Many modern ships are now built with increasingly advanced corrosion-resistant coatings, and efficient cathodic protection systems to help minimize the effects of corrosion.

3. Human Error

Human error remains one of the leading causes of ship accidents. Navigational mistakes, failure to follow safety protocols, poor decision-making during high-stress situations, or even basic negligence can lead to shipwrecks. For example, if a ship sails into dangerous waters without properly assessing the weather conditions, or if the crew fails to manage the load properly, the consequences can be disastrous.

In some cases, human error has led to ships colliding with rocks, reefs, or other vessels, causing significant damage or even sinking. Misjudging weather patterns or failing to understand the limits of the ship’s capabilities (e.g., its weight capacity or engine power) can also result in a loss-time breakdown.

Preventive Measures: Proper training and continuous drills for the crew are essential for minimizing human error. Advances in technology, such as automated navigation systems, can also reduce the likelihood of mistakes. Moreover, a better working culture and more stringent regulations for safety practices can go a long way in improving outcomes.

4. Weather and Natural Forces

The sea is unpredictable, and extreme weather conditions can wreak havoc on even the most robust ships. Storms, hurricanes, and tsunamis generate powerful waves and winds that can push ships to their limits. If a vessel encounters waves or currents higher than its design can withstand, it could suffer catastrophic damage.

In addition to strong winds and high seas, icebergs and shifting ice floes in polar regions can also present a significant risk to ships, especially those not built with ice-breaking capabilities.

Preventive Measures: While we can’t control the weather, modern ships are equipped with advanced weather forecasting systems that allow crews to anticipate and avoid dangerous conditions. Ships are also designed to handle a certain level of stress, but crews are trained to navigate carefully, especially in known storm-prone regions.

5. Mechanical Failures

Like any complex machine, ships are made up of hundreds of components that must all work together to ensure smooth operation. Mechanical failures—such as engine malfunctions, pump failures, or problems with steering systems—can lead to breakdowns or accidents. A sudden engine failure, for example, could leave a ship stranded in the middle of the ocean, potentially putting it at risk for sinking or being hit by another vessel.

Preventive Measures: Routine maintenance is crucial for keeping a ship’s mechanical systems in working order. Advances in predictive maintenance technology allow engineers to monitor and assess the health of critical ship components in real time, detecting issues before they become failures. Additionally, redundancy in key systems ensures that the failure of one part does not result in a total loss of functionality.

6. Cargo Problems

Improper loading, securing, or transporting cargo can also lead to ship breakdowns. Overloading a ship or unevenly distributing its weight can cause the vessel to list or capsize.

Additionally, poorly secured cargo can shift during transit, destabilizing the ship and possibly damaging the hull or other vital systems.

Preventive Measures: Strict guidelines and regulations are in place to ensure that cargo is loaded and secured correctly.

Modern ships often feature sophisticated cargo management systems, and port authorities are tasked with verifying that cargo is properly handled before the ship sets sail.

7. Collision or Grounding

Even though modern ships are equipped with radar, GPS, and other navigation aids, collisions and groundings still occur. A ship can collide with another vessel, an underwater reef, or even an uncharted obstacle, causing severe damage to the hull. These accidents often lead to flooding, which can eventually cause the ship to sink or break apart if not quickly addressed.

Preventive Measures: Improved navigation technologies, stricter maritime regulations, and better communication between ships and coast guards have all helped reduce the number of collisions. However, human vigilance remains key, as does investing in ship designs that minimize the risk of catastrophic flooding in the event of a breach.

After the Damage is Done

Even with all the preventive measures and necessary safety precautions in place, and even after all the procedures are followed correctly, accidents, incidents and failures still happen.

Depending on the severity and the operating policies of the individual asset holder(s), the procedure for following up after any damage, corrosion, or incident may differ, however, they typically would include the following:

• Immediate mitigation of any present or further damages; arresting of any pending emergencies and identifying and assessing any Safety Critical Elements that may have been effected
• Thorough inspection of the affected areas and or components, with a full damage/risk assessment
• Detailed investigation of the sequence of events leading up to the event
• Create a plan for the renewal, isolation or repair, to restore components back to a safe working state
• Execution of the plan
• Continued monitoring
• Renew operating procedures, and safety & maintenance protocols as required, to minimize the risk of future incidents going forward

Its important to note, in the event where assets owned by two separate parties are involved in an incident, an immediate inspection and subsequent repairs may need to be executed at the request of the insurance companies.

Conclusion

Ships are marvels of engineering, but they are not invincible.

Structural stress, corrosion, human error, extreme weather, mechanical failures, cargo mismanagement, and collisions are all factors that can contribute to a ship breaking down.

Fortunately, advancements in shipbuilding, maintenance practices, and technology continue to improve the safety and reliability of these vessels.

By understanding these risks, the maritime industry can take steps to minimize failures and ensure that ships continue to safely navigate the world’s oceans for years to come.

Furthermore, in many cases subsea intervention, by utilizing divers, can play a major role in the prevention of major incidences. Through regular underwater inspections, divers can highlight any anomalies and execute a repair plan, arresting any problems before they occur.

Thai Subsea Services, continue to strive as a “full service company”. Dealing with situations after an incident is always an uncomfortable and often traumatic time for everyone involved. Our experienced team understand these situations well and work closely with our clients, guiding them through the difficult times. Our divers and technicians are able to advise on the most cost-effective solution, often onsite and are able to execute the work in the shortest amount of time, getting the vessels back out to sea and avoiding any downtime.

Why Conduct Underwater Ship Services in Thailand?

Thailand, with its strategic location in Southeast Asia, has long been a hub for maritime trade and services. Furthermore, when it comes to maintaining the integrity and safety of ships, underwater ship services are an essential aspect of the maritime industry.

As the world’s shipping industry continues to expand, conducting ship services in Thailand is becoming an increasingly attractive option for businesses looking to maximize efficiency, reduce costs, and benefit from a range of unique advantages.

Among these services, underwater ship maintenance stands out as a crucial area in which Thailand excels.

In this blog, we will explore why Thailand is the ideal location for conducting underwater ship services.

Strategic Location for Maritime Trade

Thailand sits at the heart of Southeast Asia, offering a prime location for all kinds of shipping services. It is surrounded by vital global trade routes that connect Asia to the Middle East, Europe, and the Americas.

The country’s proximity to key markets like China, India, and Australia makes it an ideal base for conducting international maritime operations.

Hosting some of the busiest ports in Asia, including, Laem Chabang, Map Ta Phut and Songkhla are essential gateways to the South China Sea, which are some of the most significant maritime trade routes in the world.

Whether its hull cleaning, propeller maintenance, or underwater inspections, vessels passing through Thai ports and anchorages can conveniently access professional underwater services, reducing downtime and increasing operational efficiency.

Advanced Maritime Infrastructure

Thailand has made substantial investments in its maritime infrastructure, resulting in world-class facilities that support a range of ship services.

The country is home to modern ports with state-of-the-art cargo handling, and maintenance facilities.

In particular, Laem Chabang Port, the largest and busiest port in the country, boasts a comprehensive set of services, including container and bulk goods terminals, dry docks, ship repairs, and maintenance support.

However, due to the ever-increasing expense and limited availability of dry-docking facilities – not just locally, but worldwide –  ship owners and operators are more commonly turning towards underwater ship service providers, such as Thai Subsea Services, to assist them with their maintenance needs.

Additionally, Thailand is home to several other key maritime hubs, ensuring that companies can access reliable, high-quality services across various locations.

Cost-Effective Services

One of the most appealing reasons for conducting ship services in Thailand is its cost-effectiveness. Compared to other maritime hubs in the region, such as Singapore or Hong Kong, Thailand offers competitive pricing without compromising the quality of services.

Also, compared to other regions, subsea services are generally available in even the most remote locations within Thailand. This is a key advantage for smaller crafts working in smaller ports, who do not have to set voyage for long distances to have their needs met.

Labor costs in Thailand are relatively affordable, and skilled workers, including maritime engineers, technicians and commercial diving contractors are readily available.

This significantly reduces the overall cost of operating and maintaining ships, providing an attractive proposition for ship owners and operators looking to improve their bottom line.

An Idyllic Setting

Thailand is known the world over for it’s serene coastlines with warm and clear skies and seas.

Such favourable natural conditions make Thailand an ideal location for carrying out all types of underwater work.

Blessed with superb weather nearly year-round, “no diving” days due to poor weather conditions are rare. This means you can rely on underwater services being available at any given time.

Conclusion

Thailand is a prime location for conducting ship services, thanks to its strategic location and idyllic setting, advanced infrastructure, and cost-effective services.

For businesses looking to streamline their shipping operations and maximize efficiency, Thailand provides the perfect base to conduct ship services.

Thai Subsea Services Ltd. is the leading underwater ship services contractor in Thailand, offering a wide range of bespoke solutions to all ports and anchorages nationwide.

Through excellent customer relations and transparent pricing structure, TSS has gained a reputation as the preferred contractor in the country.