Recovery and Changeout of SUTU

Recovery and Changeout of SUTU at 33m depth

EMEC is the European Marine Energy Centre, which is based in Orkney. It encompasses several tidal energy test sites including grid-connected tidal turbines and wave test sites, located at Warness. This site was chosen because of its high velocity marine currents which can reach 7-8 knots at spring tides in the natural channel between the Atlantic and North Sea. Such conditions necessitate the use of a highly experienced dive team.

EMEC’s test sites are connected by an underwater infrastructure, which terminates in a four mooring SUTU at Warness. The SUTU is a critical subsea system that allows many subsea control modules to be connected to the same communications, electrical and hydraulic supply lines. The Warness SUTU had developed a serious fault that required urgent repair.

RockSalt were contacted to undertake the diving work after the previous contractor was no longer involved in the project. The RockSalt dive team were mobilised to disconnect the SUTU and return to the surface for the client to conduct the necessary repair works. Once the repairs had been completed, the dive team returned the unit to the seabed and completed the necessary connections.

Surface Supplied Air Diving was carried out from the Green Marine Green Isle diving support vessel. This was mobilised from the quayside at Kirkwall Harbour. The dive system consisted of a 2-diver air panel, breathing from passive air banks installed on the vessel.

The biggest challenge on this project were the poor tidal conditions which restricted the diving window down to a handful of minutes to complete the dive works in returning the SUTU to the seabed. Fortunately, our highly skilled divers were able to complete the project successfully in difficult diving conditions.


Recovery and changeout of SUTU at 33m depth.

Dive Systems


Case Studies

Diving Services for recovery and changeout of SUTU Subsea Termination Unit

Recovery and Changeout of SUTU

RockSalt provided diving services as part of a recovery and changeout operation for a SUTU Subsea Termination Unit at EMEC’s ...

Single buoy mooring diving project, Ireland - RockSalt Subsea

Annual Inspections of Single Buoy Mooring

RockSalt Subsea provides annual pre-berthing inspections of a single buoy mooring, where the CP and UT readings are recorded up ...

RockSalt Subsea Engineering & Technical Authority

Personnel Supply for New Build Vessel

Supply of Personnel - New Build Vessel The Atair is a research vessel, which was built in Germany. It commenced ...

RockSalt Subsea - Dive System 1

Diving Team Call Outs

Diving Team Call Outs It’s not uncommon for vessels to encounter obstructions that require inspection and removal. This can often ...

OPT Buoy De-ballasting - RockSalt Subsea, March 2019

OPT Buoy De-Ballasting

The Project RockSalt provided diving services for a client at Nigg Port for OPT Buoy De-Ballasting. Diving Mode of Operation ...

Rothesay Ferry Terminal – Scour Baffle Installation

Rothesay Ferry Terminal – Scour Baffle Installation

Rothesay Ferry Terminal - Scour Baffle Installation Rothsay harbour lies on the Isle of Bute on the west coast of ...


Head Office
Unit 9
Insch Business Park
Insch, Aberdeenshire
AB52 6TA
Tel: 01464 821739

Newcastle Office
Blyth Workspace
Commissioners Quay
Quay Road, Blyth, UK
NE24 3AF
Tel: 01670 338544

© Privacy Notice | Cookie Policy | Disclaimer | RockSalt Subsea Ltd. is registered in Scotland. Company no SC52449 | VAT no 233855009.