Marine Renewables

At J+S, we recognise that the Offshore Industry brings challenges in getting power and control information from energy conversion devices to shore.

Rugged and flexible solutions

Our Marine Renewables Systems offer clients proven, rugged and flexible solutions for onshore and offshore implementation. Our proven track record and expertise have also allowed us to begin working on the next generation of connectors to reduce installation and connection times for the operator.


The J+S dry-mate connector allows high voltage power to be transferred from tidal and wave generation systems through various sized composite cables comprising power cores, system control (fibre optic cores) and cable communication cores.

The J+S solution provides a pressure balanced make and break connection allowing generators and cables to be safely deployed and connected. The termination was designed to be virtually Partial Discharge (PD) free, required for test and development installations. It can be configured as a pass-through connection or testable stop-end. In the latter mode it allows full monitoring, energisation and testing of the terminated cable from the shore.

Terminated cables are then converted to a splice or in line connection to connect to a generator.

The connection can at any time be returned to a stop-end termination without the need to replace the assembly therefore minimising costs.

Key Features

System Description


The latest Mark V version of the J+S fastmate connector is designed to reduce pre-assembly and offshore installation time to an absolute minimum.

Mark V Receptacle Connector

The receptacle connector assembly is a cylindrical assembly directly mounted onto the end of the umbilical. The connector is designed to interface directly to the Mark V Plug connector.

The following elements are incorporated into the design;

Mark V Plug Connector

The plug connector assembly is a cylindrical assembly directly mounted onto the end of the umbilical. The plug connector is designed to interface directly to a receptacle connector or into a distribution or transformer hub with receptacle connector interfaces.


The J+S connector hub interfaces with Mark V connections to accept a standardised connector fitted to import and export umbilical cables. Connections would be dry-mate connections made on the deck of a suitable support vessel.

Subsea Connector Hub - 3 way

The J+S connector hub interfaces with Mark V connections to accept a standardised connector fitted to import and export umbilical cables. Connections would be dry-mate connections made on the deck of a suitable support vessel.

Key Features

Subsea Connector Hub - 5 way

The 5-way connector hub assembly will be a standalone assembly similar to the 3-way hub but with 5 Mark V receptacle interfaces mounted on one end. The female interfaces are designed to interface directly to Mark V plug connectors for connection to 4 of generator inputs and output service connection.

The connector hub could also be daisy chained with up to 3 generator inputs connected into a ring main.


J+S have experience and capability to provide support for Medium Voltage connector termination and splice repair work both on and offshore. We have our own offshore rated habitat that can provide a safe and sheltered working environment on the back deck of a vessel.

Contact Us

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Phil Reid Managing Director >>

Phil has worked in the oil and gas 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 will oversee the day-to-day operations and 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 Oil & Gas 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. 

Simon Smith – Business Development Director
Simon has worked in the oil and gas sector for over 20 years. He started his career as a planning co-ordinator for offshore development systems and has since been involved in both surface and subsea operation management both locally and overseas with Wood Group, Plexus Ocean Systems and Cameron’s before joining J+S Ltd in 2012 as a Senior Account Engineer. J+S Ltd then became part of SEA Ltd and the Cohort Group where Simon was promoted to Business Development Manager in 2019 before taking part in the management buyout of the Aberdeen based subsea division of SEA to form J&S Subsea Limited.
Simon initially studied Electronic and Electrical Engineering at Edinburgh University and later Engineering Design at The Robert Gordon University and recently became a Certified Project Management Associate through APM. Simon has experience with on and offshore support along with efficiency and safety control and has utilised this to deliver large scale projects for international clients in the energy industries.
As part of J&S Subsea limited, Simon plans to help grow the Subsea Energy business both in the UK and globally while championing a circular economy focus to help provide a better future.
Simon Smith

Matthew Blair – Executive Chairman

Matt Blair is 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.  Matt works closely with Oil company subsea engineering and production controls departments, supporting their subsea operational assets. 

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

He is Vice Chair of the Decom Leadership Group of Decom North Sea and in that role has facilitated industry and academic studies on potential for reuse and repurposing of decommissioned equipment.   

Matt is seeking further opportunities to update and transfer Oil and Gas technologies and products into the Marine Renewables markets and help to develop the broader circular economy.