Reef installed 124 inter array cables over the course of 20 months at the Gwynt y Môr Offshore Wind Farm, owned by RWE Innogy and partners.

It is the largest project the company has completed to date and will be used as a benchmark against forthcoming offshore wind farm work.

The project has been a "fundamental part" of the company's last two years, during which it invested £5m in specialised subsea equipment which it used for the first time on the wind farm.

Duncan MacPherson, chief executive at Reef Subsea, said when the company was awarded the project in 2012 he knew it would be tested by it.

"To complete a project of this size is a great way to end the year and gives us inspiration for the projects ahead," he added.

RWE Innogy UK’s project director for Gwynt y Môr Toby Edmonds, said: "The completion of array cables has brought to an end the installation phase at Gwynt y Môr and we are now focusing on final commissioning of the last remaining turbines."

While working on the project, Reef awarded significant services to a number of companies including the provision of crew transfer vessels, diving and cable installation support and supply of cable protection. The project employed upwards of 250 staff per day at the height of construction and has made a "significant contribution" to the renewables subsea industry.

RWE expects that the wind farm will be fully operational in early 2015 and will supply power for up to 400,000 homes.