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 High 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

Enquiry Form
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 joined the Royal Navy from school where he successfully completed a 5-year Marine Engineering Apprenticeship. After 10 years’ service he started a career in hydraulic systems design, manufacture and project management.
After 5 years working in the hydraulic service industry James moved to Kvaerner Oilfield Products as a Support Engineer providing engineering support for production and service teams within the controls group. He was also responsible for the design, manufacture and offshore operation of the Control System Well Monitoring Equipment for Shell assets used during well intervention testing.
Whilst at KOP he completed an Open University Postgraduate Diploma home study course in Manufacturing: Management and Technology
He subsequently moved to RRC Controls Services where he was solely responsible for all the mechanical and hydraulic design of the company’s successful diver installable Subsea Control Module. Over 10 years at RRC he designed and built a range of bespoke subsea equipment from electrical and hydraulic Subsea Distribution Assemblies to Chemical Injection Flowmeter housings.
On moving to J+S Ltd as a Senior Engineer James continued to be responsible for design of subsea and renewables equipment including a new design ROV installable Subsea Control Module and next generation Medium Voltage dry-mate connection systems. During his 10-year tenure at J+S Ltd and SEA James has been promoted to Principal Engineer and then to Engineering Manager.
James has a wealth of knowledge in Project Management and design processes, using Solidworks 3D and document management software to produce highly configurable product designs in very short timescales.
As Engineering Director at J&S Subsea Limited, James looks forward to developing the engineering capabilities of the business, providing innovative designs, high quality products and responsive service to the Subsea Energy Industries.
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 has worked with SEA and previously J+S Ltd for over 10 years and has a wealth of industry knowledge and expertise. Matt works closely with Oil company subsea engineering and production controls departments, supporting their operational assets
Matt worked with Ferranti Computer Systems Ltd in the naval simulation group and through his extensive experience in electronics and sonar, moved into hydrographic survey working with Subsea7, Tritech, and CDL before joining J+S Ltd.

Matt has lead the management buyout of the Subsea Engineering division of SEA for J&S Subsea Limited and is seeking opportunities to transfer technologies and products into the Oil and Gas and marine renewables markets.