WIND park developer Navitus Bay has started drilling sea bed bore holes off the Isle of Wight.
The company, which wants to build up to 194 wind turbines around 11 miles off the south west coast of the Island, is extracting cores of sea bed material to gain a better understanding of its character.
Project director Mike Unsworth said: "This latest investigation is the next step in the process of engineering an optimum design for the wind turbine foundations."
Work started earlier this month by Bristol-based geotechnical survey specialists, Horizon Geosciences Ltd, which is using a vessel fitted with special water jets that hold it stationary in the water to allow accurate drilling in tidal swells.
Fifteen sets of soil samples at various depths will be taken.
The survey comes shortly after Navitus Bay had its application for Development Consent Order accepted by the Planning Inspectorate.
Developers are still awaiting planning permission, which will be determined by the Secretary for the Department of Energy and Climate Change. An Isle of Wight Council report on the plans, as part of the consultation, said they believed Navitus Bay developers had underplayed the visual impact on the Island.