ROV/Subsea/Diving inspections

subsea new

ROV/Subsea/Diving Inspections

Our Marine Class department was formed through the amalgamation of Kelaj’ ROV specialists and our industry-leading Marine Class team to form a single, cohesive unit that prides itself on its pro-active, solutions-based approach. We specialise in statutory inspections for the classification of ships and offshore floating structures and subsea inspections using the latest ROV technology, proprietary inspection tools, and cutting-edge software solutions.

Our team can provide unmanned ROV, RDVI, drone, or robotic crawler inspection services to complete hull UWILD, In-Water Survey, mooring chains, riser, and tank inspections. The Asset Deployed ROVs can be deployed for underwater Class inspections of oil and gas industry Mobile Offshore Drilling Units (MODU), Floating Production Storage and Offloading (FPSO), and FSO vessels and platform jacket structures.

Our project managers, ROV teams, and asset inspectors work with clients to perform subsea inspection campaigns tailored to suit the specific class requirements and facility needs using our proprietary Class Survey System (CSS).

Pushing the boundaries in innovation is our ‘link-to-shore’ capability which allows clients to see the inspection in real-time. This not only gives the client a completely new understanding of the work we do, but it also keeps them much more involved. Our survey planning process is continually refined to help our clients streamline operations and is a key factor in obtaining the most favorable conditions. If weather or SIMOPS should prove an issue, our team is trained to quickly adapt, being able to perform tank and other onboard inspections to remain useful and utilised during delays.

Asset Deployed ROV systems are designed to eliminate or largely reduce downtime on subsea inspection campaigns to target ‘Zero Downtime’. Each system is designed to optimise the in-water operating limits and the multidisciplined ROV inspection teams can be qualified to perform fallback works such as Rope Access, topside NDT, RDVI, or internal ROV water ballast tank inspections.

ROV Capability to deliver

The Geo Oceans subsidiary of Vertech is a specialist provider of ROV inspection services and has developed asset deployed ROV technology to provide clients with reliable, safe and cost-effective alternatives to traditional manned inspection, commercial diving or work-class ROV inspection services.
Geo Oceans regularly use this cutting-edge technology to complete facility deployed subsea surveys, asset inspections and ocean mapping for many of the largest oil and gas operators.
Working with group member Sonomatic, bespoke NDT tools for the ROV are created to allow implementation of advanced NDT inspection solutions.


Dive resources
rov inspection

Rov equipment specifications

HPV-ROV (High Powered ROV)
Our biggest & most powerful ROV for campaigns that require a cumbersome payload.
CSS-ROV (Class Survey System ROV)
Our most versatile ROV with flexibility to perform NDT & cleaning in many environments, and is ideal for internal tank inspections or external jacket, hull, mooring and pipeline inspections.
Weighs 30kg.
ADV-ROV (Advanced Robotics)
Latest ROV technology where dexterity and finesse are critical to the subsea task. Has 5-function robotic arms perfect for controlling highly sensitive NDT tools.
RAP-ROV (Rapid Development)
Designed for rapid deployments on time- sensitive ROV campaigns. Maintains high quality image acquisition and UTM NDT capabilities.
Weights 15kg.


rov spec
rov spec2
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ACFM Actuator and Probe Mounted

Mini ROVit

mini rov

ROV FPSO uwilds – hull, risers and moorings

rov fpso

ROV project experience & history


Structural Inspection


Underwater/subsea inspection is part of offshore Oil and Gas industry under the upstream segment. As the name implies, it is about inspecting the underwater part of the oil and gas structures located offshore such as platform, pipeline, FSO/FPSO, buoy mooring and deepwater facilities. The area submerged below the sea surface which can be magical and perilous at the same time.  

Underwater inspection is one of the components under Subsea IRM’s trident. IRM stands for Inspection, Repair and Maintenance. Some calls it as IMR which is also correct, it is just how you want to arrange the alphabet. While underwater inspection can be done independently without any repair or maintenance work, the need to record data for repair and maintenance work would almost certain require inspection task to be involved as well.

Subsea IRM/IMR may not be widely known to people outside the industry compared to FEED, EPCIC and T&I but it is an integral part in the lifecycle of an offshore structure. To make it more important as the structures are located underwater – you cannot just simply walk and have a look like walking on topside of a platform. It requires specialized personnel from various disciplines such as diving team, ROV team, the vessel crew onboard a Dynamic Positioning (DP) vessel, surveyor team and the 3.4U inspection team. That is on top of specific equipment and methodology to perform subsea operations.


Mooring Chain Inspection –

3D mooring chain integrity inspections represent one of the toughest subsea measurement challenges; regardless if delivered via ROV or by diver. Dynamics of both the chain catenary and the measurement platform are sensitive to environmental conditions; this can limit the window of operations particularly if the chain requires cleaning, the mounting of a calibration target or the use of a vernier-type caliper.

The precision, accuracy and resolution of a meaningful ‘digital twin’ must be better than +/-0.15mm to enable year-upon-year comparisons between successive campaigns and the identification of progressive wear and corrosion.

3D Scanners

Savante provides a complete range of measurement sensors for the delivery of high-integrity chain measurement results remotely or with an on-site surveyor. In this section we present a brief overview of the advantages, risks and limitations of each technique. For ROV based operations, these include both contact and contact-less systems including;

3DGP: Retrospective photogrammetry with scaled-object
3DGP: Monocular Vector HD photogrammetry and Scale-Board
Contactless- Vergence: Stereo SLAM Photogrammetry
Contactless - DLS-350: 3D Laser SLAM mapping.

Subsea Repair & Maintenance

Kelaj has a wealth of experience in completing subsea maintenance, repair and cleaning services using a fleet of Mini-ROV observation class systems equipped with a range of custom tooling.

Kelaj integrate state-of-the-art cameras, sensors and manipulator technology onto small, powerful and agile Mini-ROVs to provide capabilities traditionally only possible when using large work class ROVs or divers, which also require costly dive support vessels.

Deployment of subsea tooling
Rotary brush cleaning
Mechanical chippers and cleaning tooling
Laser scanning, 3D modelling
Actuators & five function Manipulators
Hull penetration plug installation
Construction Support
Full site of inspection & NDT systems to assist in quantifying repair plans and integrity
Significant reduction in carbon emissions

Hull and Mooring In-Water UWILD

Using Mini-ROV CSS technology we are able to conduct accredited UWILD inspections to satisfy Class inspection requirements. Inspection surveys are tailored to the individual assets, considering the age of the facility and the condition of the vessel being inspected. The survey can be broken down into overall visual status check requirements also known as General Visual Inspections and Close Visual Inspections. These visual status checks are supplemented with CP, UTMs, and other NDT tools. 

All hull penetrations and their markings can undergo a visual status check. Cleaning of marine growth may be necessary. Where safe access permits, the valves can be inspected with a small probe camera and lights, these valves can then be actuated to check if they are in good working order. Caisson strainer rings and baskets can be inspected for damage and blockage as well.

The riser, turret, and moorings of a vessel (RTM) can be inspected by deploying an ROV from the facility, eliminating the need for a support vessel operating inside the exclusion zone. All associated attachments, connections, and appurtenances can be inspected at their interface with the RTM.


Water Ballast and Cot Tanks


Utilising advanced ROV inspection technologies and CVI methods we conduct tank inspections with attending Class surveyors to meet the specific Class requirements of each asset. 

Thickness Measurement location sketches can be provided detailing the areas of the test for each structure requiring UTM. All UTM readings are recorded on the Relevant Thickness Measurement Sheets (TM1 – TM8) in accordance with the requirements of the Classification society. All UTM readings wastage allowances are automatically calculated in the TM Sheet Template.

Drawing on our extensive and successful track record in Ballast and Cot tank inspections, as well as ongoing maintenance works, Geo Oceans uses our specialised suite of data and document management tools to support project delivery through every stage of the project management lifecycle.