New robotic solution enables automated non-destructive weld testing in the splash zone

OceanTech has collaborated with SINTEF, ConocoPhillips, and DNV to develop an autonomous inspection robot for non-destructive weld testing in the splash zone. The robot simplifies asset life extension processes by providing higher-quality data and enables operators to perform eddy current testing in adverse weather conditions.

Read more

Our trusted partners: Vertikal Service

Since 2019, OceanTech has maintained a valuable collaboration with Vertikal Service. CEO Bernt Schjetne highlights the importance of cultivating long-term partnerships, engaging subcontractors early in the planning process, and strongly emphasising joint training onshore. These practices are vital for attaining optimal efficiency and safety in splash zone projects.

Read more

Best practices for cutting and removing pipes in the splash zone

The harsh conditions in the splash zone make pipe-cutting and removal projects complex. The operation carries safety risks, requires careful planning to preserve the installation’s structural integrity, and is subject to stringent regulatory requirements. Pipe-cutting projects are also time-sensitive, with delays potentially resulting in significant financial losses. 

Addressing these challenges requires a combination of experience, expertise, and meticulous planning. At OceanTech, our team of senior engineers has executed remotely operated splash zone projects since 2007. We perform cutting and removal operations on flowlines, risers, caissons, guides, braces, and brackets, and we can also perform similar tasks for the offshore wind and fish farming industries. Using our robotic solutions enables our engineering team to perform any type of repair work at offshore installations. Here are our best practices for cutting and removing pipes in the splash zone.

Choosing the right equipment and techniques

Various cutting methods are available for pipes, including mechanical cutting, thermal cutting, and abrasive cutting. It is advisable to consider accessibility, environmental factors, the pipe material, dimensions, and the pipe’s condition when choosing your method. Inspecting the installation in advance allows you to determine the pipe’s integrity and identify potential weak points. This will help you select the appropriate method.

At OceanTech, we commonly use diamond wire saws (DWS) that allow for precise and controlled cutting. These saws also reduce the amount of debris generated during the cutting process, minimising environmental impact. While certain offshore operations can employ remotely operated underwater vehicles (ROVs), the conditions in the splash zone require other equipment and techniques. Using our robotic solution for vertical cutting means we can mount diamond wire saws on vertical access tools fixed to structures. This enables improved accuracy and control in hard-to-reach areas.

The equipment required for pipe removal encompasses lifting frames, cranes, winches, or ROVs with lifting capabilities. Regardless of your chosen equipment, it should be capable of operating effectively in offshore conditions and be equipped to minimise the generation of debris and contaminants. At our Subsea Test Center in Trondheim, we test methods, equipment, and tools before deploying them offshore. This practice enables us to tailor the solution to the unique requirements of each project.

Environmental considerations

The splash zone is a unique and ecologically sensitive area where marine and terrestrial environments converge. It harbours diverse ecosystems, and disrupting this balance can have significant ecological consequences. Prior to project execution, it is crucial to assess the environmental impact of the cutting process and take measures to minimise it. 

This includes: 

  • Using environmentally friendly methods
  • Ensuring proper disposal of waste materials to comply with environmental regulations
  • Implementing containment measures to prevent debris from dispersing. For example, you may deploy debris collection systems, such as nets or screens, to capture loose particles from the cutting process.

Using support vessels is another factor to take into consideration. Reducing your reliance on support vessels allows you to mitigate emissions, minimise the risk of spills, and prevent waste discharges that introduce pollutants into the water. Our splash zone projects do not need support vessels. We control our operations from a purpose-built control unit on the topside of the installation. 

Risk assessments and safety measures

Before initiating pipe-cutting operations offshore, it is highly recommended to conduct a thorough risk assessment that encompasses potential hazards and corresponding mitigation strategies. 

You should assess factors such as: 

  • Wave action
  • Currents
  • Underwater visibility
  • Potential underwater hazards
  • Presence of flammable substances
  • High pressures
  • Confined spaces
  • The pipes’ structural integrity

Prioritise safety at all times. Adhere to company safety policies and regulatory bodies’ relevant safety regulations, guidelines, and protocols. OceanTech’s technology enables unmanned operations in close proximity to structures and within confined spaces. Our robotic solutions empower remote work, significantly reducing the requirement for human operators to physically enter the splash zone. This approach effectively mitigates the risk of injury associated with exposure to perilous conditions like wave action and strong currents.

Effective communication and collaborative planning

When project stakeholders prioritise effective communication and foster a culture of teamwork, they enhance coordination and cooperation. Although OceanTech's offshore teams are typically compact, often comprising two to seven engineers, our onshore operations boast a multitude of support teams. These are responsible for diverse tasks and functions, including HSE, quality assurance, logistics, design, data modelling, strategic planning, and technical support at our Subsea Test Center. We also collaborate with partners such as Vertikal Service AS, who provide us with rope access technicians and riggers on larger projects.

The wide range of teams and stakeholders in pipe-cutting projects requires clear communication and collaborative planning to ensure everyone understands their roles and responsibilities. Collaborative planning allows all stakeholders to contribute their expertise and insights, identifying potential project risks and hazards. It also ensures that all tasks are properly coordinated, minimising conflicts and maximising efficiency by addressing potential bottlenecks before execution offshore. Cutting and removing pipes in the splash zone requires precision to avoid damaging other structures or equipment. Collaborative planning allows for multi-disciplinary discussions on techniques, tools, and equipment.

Please note that our best practices are general recommendations. It is crucial to adhere to industry-specific regulations and guidelines and to consult with local regulatory bodies for specific requirements for your business.

Hess Corporation: Riser inspection made simple

OceanTech’s robotic inspection solutions enabled Hess Corporation to verify the condition of the South Arne platform risers.

Read more

Overcoming seasonal obstacles: Robotised solutions for caisson inspections

Caisson inspections are vital for maintaining the integrity and safety of the rig. OceanTech’s inspection capabilities enable operators to perform inspections in all seasons.

Read more

Fairlead replacements for Equinor in the North Sea

In 2019, Equinor hired OceanTech to replace riser protection net fairleads at the Snorre A platform in the North Sea. The project has enabled Equinor to continue production without costly disruptions.

Read more

Skilled personnel and collaborative approach key to successful Riser Protection Net (RPN) replacement

- The Riser Protection Net (RPN) replacement has enabled Equinor to continue its Heidrun operations without costly disruptions, Ståle Karlsen, Project Manager at OceanTech, said.

Read more

Robotic solutions vs. divers in splash zone operations

OceanTech’s robotic solutions for splash zone operations do not require the use of any offshore divers. This provides several benefits to your business, including improved safety, significant cost savings, and reduced carbon emissions.

Improved safety

Using divers in offshore operations generally carries significant risks. The environment presents a number of hazards such as poor lighting, restricted oxygen supply, and sometimes extreme temperatures or pressures. 

Offshore diving risks, however, are not limited to drowning or decompression sickness following deep dives. Inspections and maintenance work in the splash zone, the part of the offshore structure immediately above and below the waterline, also pose serious hazards to divers. Strong winds, currents, and large waves affect diving safety. In the North Sea, although partially sheltered from the Atlantic by Britain, wave heights can reach 10-15 meters or higher. But even 2-meter waves, or currents alone, can cause crush injuries when diving in confined spaces. Underwater entanglement, or marine vessel impact, can also cause serious injuries to divers.

OceanTech offers a range of tools and techniques, ranging from lightweight robotic solutions to more heavy-duty solutions with industrial standard robotic arms. All tools and techniques are designed to avoid any use of divers or support vessels, improving operational safety significantly. There is no manual handling, which would be required when using divers, and our splash zone tools allow unmanned working close to structures in the harsh splash zone environment. Our splash zone tooling also provides a stable platform that enables the deployment of sensors, cameras, probes, and other inspection tools, which would have been impossible using divers.

Significant cost savings

Safety concerns aside, using divers in splash zone operations is also expensive. Safety concerns aside, using divers in splash zone operations is also expensive. Although rates vary significantly across continents, offshore divers require a large team topside, with support vessels frequently carrying more than 50 project personnel on board. This includes divers, supervisors, technicians, ROV pilots, survey teams, client personnel, vessel crew, and others. As the scope of a task grows, so does the size of the team – as well as the cost of operation. In the North Sea, the total cost for an offshore diving operation could easily exceed EUR 100,000 per day.

A considerable proportion of the vessels in use in the North Sea are also aging and have proven to be expensive to maintain. In recent years, largely driven by the rise in oil prices, the increased demand for support vessels is pushing prices higher.

Compared to using divers, OceanTech’s approach results in superior cost savings. In an Ekofisk oil field pilot, our solutions managed to achieve total savings of EUR 1.9 million for ConocoPhillips in a single year. The Exploration & Production company had previously relied on divers. Our use of splash zone tools achieves 100% coverage internally or externally and does not require any assistance from divers, ROVs, or support vessels. The cost savings are not least due to reduced man-hours. Our robotic solutions for remote cleaning, inspection, and maintenance only require a team of 3 to 5 persons. You also avoid lengthy and costly waits due to unpredictable weather. Divers only working in the water for a couple of hours, together with the normal diver window of just a few days, leads to work completion is highly dependent on favorable weather conditions. 

The cost savings are even greater in the aquaculture industry, where businesses rely on far more frequent inspections of nets, barges, and structures. As the industry moves further and further from shore, we have the technology and expertise required to help businesses complete work in a cost-effective manner.

Reduced carbon emissions

Global attention around carbon emissions is driving major offshore companies to look at how COreleases can be reduced in production, power generation, and operations. This has been demonstrated by major companies such as Equinor, which has issued plans to cut carbon intensity in half by 2050, and Lundin Energy (formerly known as Lundin Petroleum) announced carbon neutral targets, and a name change to remove the «petroleum» reference to reflect the industry’s energy transition. Another oil and gas supermajor, BP, has also set out its ambition to become a net zero company by 2050 or sooner. 

As offshore companies look to reduce emissions from their supply chains, our technology could become part of the solution. Offshore support vessels can output thousands of tonnes of CO2 every year, as well as significant amounts of nitrogen oxides (NOx) and sulfur oxides (SOx). With OceanTech, all splash zone tools are launched from the structure itself, minimizing the need for support vessels. This enables companies in offshore oil and gas, as well as in the offshore fish farming and offshore wind industry, to cut CO2 emissions from operations significantly.

As techniques and solutions for splash zone operations continue to evolve, industry professionals are asking themselves whether to use divers or robotic solutions. While the question may be simple, the answer depends on a multitude of factors including the scope of the task, local marine environment, and project complexity. Ultimately though, everything boils down to safety, cost, and carbon footprint.

Our track record includes successful operations in the North Sea, the Gulf of Mexico, and Australia. Our team of engineers and technicians constantly seek new and innovative ways of working, to maintain OceanTech’s position as the preferred supplier of underwater splash zone tooling on a global scale.

Robotic solutions vs. ROVs in the splash zone

Robotic solutions vs. ROVs in splash zone operations

ROVs may perform better at greater depths, but in the splash zone, OceanTech’s robotic solutions offer a wide range of benefits for businesses performing underwater cleaning, inspections, and maintenance work.Read more

What is the splash zone?

The splash zone is frequently defined as a non-accessible area and poses significant challenges to operations in offshore wind, oil and gas, fish farming, and transport infrastructure. But what exactly is the splash zone? And what are the challenges in splash zone operations?

In areas with harsh environments, such as in the North Sea, it is common to assume that offshore structures located in the splash zone are not easily accessible for cleaning, inspection, repair, or modification. In fact, the world’s largest classification society, DNV, describes the splash zone as a non-accessible area.

But what exactly is the splash zone?

DNVs Offshore Standard DNV-OS-C101 provides greater detail:

«The splash zone is the part of a support structure that is intermittently exposed to seawater due to the action of tides or waves. The splash zone separates the atmospheric zone and the submerged zone, and is determined by the influence of waves, tidal variations, settlements, subsidence, and vertical motions.»

At OceanTech, we define the splash zone as the part of the structure immediately above (+20 feet) and below (-50 feet) the waterline. The condition and integrity of offshore structures in the splash zone are affected by corrosion, fatigue, and marine growth.

Corrosion, fatigue, and marine growth 

The splash zone is not only a major challenge in the offshore oil and gas industry; underwater structures in offshore fish farming, offshore wind, and transport infrastructure, are also located in harsh marine environments. Steel structures, mooring systems, pipes, risers, fish farming nets, and monopiles are all exposed to aerated seawater, UV radiation, and repeated wetting and drying.

If left unchecked, the conditions in the splash zone can result in various serious problems, including:

  • Accelerated corrosion on exposed surfaces
  • Accelerated material strength fatigue
  • Marine growth, such as algae and mussels, in some cases up to three feet thick

The potential for a neglected problem to turn into an expensive issue is considerable. In offshore oil and gas, for example, plant failure and unplanned maintenance account for nearly half of overall efficiency losses. The notoriously unpredictable splash zone, however, poses real challenges for those involved in the cleaning, inspection, repair or modification of offshore assets.

Challenges in splash zone operations

Waves and structure-induced currents are ever-changing but always present in the splash zone, making it difficult for divers and remotely operated underwater vehicles (ROVs) to perform inspections and maintenance work. Although a significant proportion of structures are aging and in urgent need of inspection, splash zone operations are often perceived as too complex, too costly, or too hazardous.


Unlike deep-water environments, where divers and ROVs can function relatively undisturbed, the dynamic splash zone presents a number of specific hazards to both humans and technology. Variations in weather conditions, in particular, combined with the proliferation of pipework in the splash zone, create unpredictable circumstances for divers and ROVs.


 Traditional splash zone operations using divers and ROVs may be both time-consuming and costly. The normal diver window is only a few days, and work is highly dependent on favourable weather conditions. This means that the estimated costs of a work scope can increase significantly. There are also direct costs involved. Splash zone maintenance and repair has traditionally required the use of a diver support vessel at an approximate cost of EUR 180,000 per day.


 The difficulties presented in this environment can often make it too dangerous to work using traditional methods, such as rope access and diving. While working in confined spaces, crush injuries are always a risk, and the swell can disturb buoyancy and make it difficult to hold an exact position while working. 


 Offshore energy companies need to adhere to regulations, as well as design and operational standards. Environmental regulations, in particular, are becoming increasingly important. Non-compliance with laws and regulations can lead to heavy fines and possibly further complications. Owners of splash zone areas thus have a huge responsibility to ensure that equipment is maintained in accordance with the regulations.

OceanTech’s splash zone tools 

 What we are seeing is that the offshore wind, oil and gas, and fish farming industries are increasingly focused on finding alternative solutions to traditional methods. At OceanTech, we offer a wide range of innovative tools and techniques, from lightweight robotic solutions to more heavy-duty solutions with industrial standard robotic arms. All the tools and techniques are designed to avoid any use of divers, ROVs, or support vessels. 

The technology is developed for all underwater cleaning, inspection, repair, and modification services, and can be launched from any offshore structure. Our capabilities include:

  • Remotely operated robotic solutions for the cleaning of marine growth, or the removal of corrosion prior to inspection or repair
  • Visual and NDT services for the splash zone and underwater structures. Our robotic solutions provide a stable platform that enables the deployment of inspection tools which would be impossible using divers and ROVs
  • All repair solutions required in the splash zone, including corrosion protection, reinforcement, wrapping repair, and surface blasting
  • Modification services in the splash zone, including modifications of existing structures such as offshore platforms, bridge columns, port constructions, offshore wind turbines, and fish farming structures

Our services are often offered as a turn-key solution, and provide several benefits, including cost savings, efficiency and safety gains, reduced CO2 emissions, and regulatory compliance:

  • With no need for divers, ROVs, or support vessels, our innovative approach delivers superior cost savings in comparison to traditional methods
  • The technology is highly efficient and operates using all standard types of ROV subsea tooling. It offers great HSE benefits too, as there is no manual handling involved
  • Our robotic solutions are environmentally friendly, as they reduce CO2 emissions significantly by reducing the need for support vessels
  • We are familiar with both offshore regulations and requirements, in addition to design and operation standards. Our track record includes multiple operations in the North Sea, the Gulf of Mexico, and Australia

By utilizing OceanTech’s technology, the splash zone is no longer a non-accessible area.