In recent years, the international demand to produce green energy has been growing to address the issues of energy security and climate change. To date, wind technology has presented most maturity due to high availability of wind resources. Erecting wind turbines offshore, however, presents significant new engineering challenges. Offshore foundations for these energy converters must be able to resist large overturning moments as well as numerous cycles of lateral loading caused by waves and wind. Thus, the need for an efficient cost-effective foundation to support the turbines is becoming more important. In this paper, a specific design of a gravity base foundation system developed for offshore wind turbines is considered. The foundation is a conical hollow concrete gravity type structure which rests on the seabed and utilises its self-weight to support the turbine. A scale-model of the proposed foundation has been experimentally tested at the University College Dublin (UCD) test site in Blessington, Ireland. The structure’s performance has been analysed under a range of supporting conditions from the absence of pile foundations to the incorporation of piles. This paper presents the findings of this research.