Testing & Commissioning

J+S Subsea provides comprehensive testing and commissioning support for subsea control systems, helping operators verify equipment performance before installation, during offshore operations and throughout the asset lifecycle. Our experienced engineers deliver practical testing solutions that give confidence in system integrity before equipment enters service.

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Confidence Before Equipment Goes Offshore

Testing and commissioning are critical stages of any offshore project. Before equipment is deployed, operators need confidence that electrical, hydraulic and fibre optic systems will perform as expected in demanding subsea environments.

J+S Subsea provides a range of testing and commissioning services to verify equipment integrity, identify potential issues and support safe, reliable offshore operations. Whether supporting new installations, planned maintenance or decommissioning projects, our engineers help ensure systems are fully prepared before mobilisation.

Our Testing & Commissioning Services

Electrical Testing

Hydraulic Testing

Fault Diagnostics

Fibre Optic Testing

Insulation Resistance (IR)

TDR & OTDR Testing

System Commissioning

Offshore Testing Support

Typical Applications

  • New Equipment Commissioning
  • Offshore Installations
  • Planned Maintenance
  • Subsea Control Systems
  • Umbilical Testing
  • Fault Investigation
  • Asset Life Extension
  • Decommissioning Projects

Frequently Asked Questions

We provide electrical, hydraulic and fibre optic testing, together with insulation resistance testing, TDR, OTDR and fault diagnostics to support subsea control systems.

Yes. Our engineers carry out testing and commissioning activities both onshore and offshore, supporting planned campaigns and operational requirements.

Yes. We believe understanding the root cause is essential before recommending repair or replacement. Our diagnostic capabilities help identify issues quickly and accurately.

Yes. Equipment can be fully inspected, tested and verified before mobilisation to reduce offshore risk and improve project readiness.

Yes. We provide testing support for decommissioning, reconnection and asset life extension projects across offshore operations.

Need Testing & Commissioning Support?

Whether you’re preparing for mobilisation, investigating a fault or commissioning new subsea equipment, J+S Subsea provides practical engineering support to help ensure your systems are ready for service.

Contact Our Engineering Team
Mark Patterson Non-Executive Chair

Mark Patterson

Non-Executive Chair

Mark’s career spans five decades, marked by entrepreneurial success and visionary leadership across various sectors, including offshore marine technology, subsea oil and gas, green energy storage, and more.

With a track record of leading businesses through start-up, growth, acquisitions, and transformations, Mark’s expertise lies in strategic decision-making, mentoring, and brand management.

He has overseen multimillion-pound projects, pioneered new technologies, and guided companies to international recognition, such as the underwater GPS NASNet®.

His leadership style is direct, inclusive, and based on trust, empowering teams to excel.

Mark’s achievements include managing high-profile global companies, such as Balmoral group, Nautronix and Well-Safe Solutions, where he played key roles in groundbreaking projects. Global explanation and high growth.

Outside of business, Mark is deeply committed to family and charity work, with a passion for shooting, boating, and car collecting. As an experienced executive, he remains dedicated to fostering success by identifying future opportunities and mentoring the next generation of leaders.

Mark Patterson Non-Executive Chair

Mark Patterson

Non-Executive Chair

Mark’s career spans five decades, marked by entrepreneurial success and visionary leadership across various sectors, including offshore marine technology, subsea oil and gas, green energy storage, and more.

With a track record of leading businesses through start-up, growth, acquisitions, and transformations, Mark’s expertise lies in strategic decision-making, mentoring, and brand management.

He has overseen multimillion-pound projects, pioneered new technologies, and guided companies to international recognition, such as the underwater GPS NASNet®.

His leadership style is direct, inclusive, and based on trust, empowering teams to excel.

Mark’s achievements include managing high-profile global companies, such as Balmoral group, Nautronix and Well-Safe Solutions, where he played key roles in groundbreaking projects. Global explanation and high growth.

Outside of business, Mark is deeply committed to family and charity work, with a passion for shooting, boating, and car collecting. As an experienced executive, he remains dedicated to fostering success by identifying future opportunities and mentoring the next generation of leaders.

Phil Reid Managing Director J+S-Subsea

Phil Reid

Managing Director

Phil has worked in the energy industry for over 25 years. He started his career with Kvaerner FSSL progressing through a variety of roles in subsea engineering, from manufacturing to leading some of their most complex projects all over the world. He worked with the original J+S for a period before moving on to Genesis Oil and Gas as a Subsea Controls Engineering consultant; during that period, he was seconded to Centrica Energy (now Spirit Energy) which led to a permanent role as Lead Subsea Controls & Umbilical Engineer for Developments, Capital Projects and Operated Assets. For almost a decade Phil successfully delivered Capital Projects from concept right through to project close out whilst also looking after the running of their subsea assets.

As part of J&S Subsea limited, Phil oversees the day-to-day operations and will grow the business both in the UK and globally. 

James Morris

Engineering Director

James’s career started when he joined the Royal Navy from school as an Artificer Apprentice. After a 5-year Marine Engineering Apprenticeship he served in surface ships HMS Glamorgan, HMS Edinburgh, and HMS Glasgow and at Rosyth as part of an engineering support team. 

Moving into the Energy Industry in 1992, over the next 26 years he gained a wealth of experience within large and small companies on operation, design and project management of subsea control systems and equipment. This period started with several years as a Project Engineer for a family run hydraulic services company Grampian Hydraulics followed by 5 years as a Support Engineer at Kvaerner Oilfield Products.  James joined RRC Controls Services ltd in 2001 before finally moving to J+S Ltd in 2010. At J+S his dedication and technical capabilities were rewarded with several promotions until becoming a member of the management buyout team. 

He has designed an extensive array of subsea equipment from basic cable penetrators to complete subsea control modules. 

James thrives on providing solutions for client’s problems. 

As Engineering Director, James will ensure that the company provides clients with timely, cost effective and technically sound solutions and services. 

Matthew Blair

Executive Chairman

Matt Blair is Executive Chairman of J+S Subsea which was formed in October 2020 through a management buyout of the Subsea Engineering Division of Systems Engineering and Assessment Ltd.

With J+S Subsea and SEA for over 14 years, Matt has a wealth of industry knowledge and expertise.

Previously an Electronics Engineer with Ferranti Computer Systems Ltd specializing in sonar and submarine command systems, Matt moved into hydrographic survey working with Subsea7, Tritech, and CDL before joining J+S Subsea.

He was Vice Chair of the Decom Leadership Group of Decommission and in that role, he facilitated industry and academic studies on potential for reuse and repurposing of decommissioned equipment. He is still actively involved with the reuse agenda through Decommission and OEUK.

Although not part of day-to-day operations, Matt stays close to company strategic matters and is seeking further opportunities to update and transfer Energy technologies and products into the Marine Renewables markets and help to develop the broader circular economy.

Contact Us

  • J&S Subsea Limited
  • The Lombard Centre
  • Kirkhill Place
  • Dyce
  • AB21 0GU
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