The wind farm occupies a 41km² area located 100km off the coast in the German North Sea.
The charter is expected to continue until at least February 2015, with the option to extend the contract further.
The Reef Despina multi-purpose DP2 construction support vessel will be used in the project, which is situated in the German Exclusive Economic Zone (EEZ), 180km away from the Bremerhaven Emden in the north-west.
Reef Subsea will offer field support to commission 80 5MW Areva offshore turbines.
Reef Subsea chief executive officer Duncan MacPherson said: "We are delighted to have secured this work scope with respected client, AREVA Wind GmbH. We look forward to working with AREVA to add value to the Global Tech I project and build a long-term, mutually favourable relationship."
Upon completion, the project is expected to generate 1,400GWh of energy per year, which is enough to serve 445,000 houses in the region with an average consumption of 3,130kW hours annually.
Global Tech I Offshore Wind is the project company that will build and operate the facility.
Other shareholders in the project include Stadtwerke München, HSE and Axpo Holding, Esportes Offshore Beteiligungs, Norderland Projekt and Windreich.
Image: Reef Subsea will provide field support in the Global Tech I wind farm in Germany. Photo: Courtesy of xedos4/FreeDigitalPhotos.net.