SSE, one of the main investors behind the test centre, announced in September that the second base, which will be used for the Mitsubishi turbine, had difficult ground conditions, causing challenges and delays in the programme.
The foundation for the Mitsubishi turbine is due to be completed in spring, and the turbine will be delivered in May.
An SSE spokesperson said construction activities will continue over the winter months, with the first main concrete pour for the SeaAngel's base taking place in mid-January.
Variable ground conditions resulted in a re-analysis of the base design and, as a result, the piles were driven deeper than originally anticipated and the amount of reinforcement within the concrete foundation was increased.
The 24MW Hunterston offshore wind test centre in North Ayrshire, which will feature three prototype wind turbines tested on land, is being developed by utility SSE and Scottish Enterprise.
Siemens’ 6MW turbine was installed at the first berth on 14 October.
The third berth will be operated by Scottish Enterprise. SSE said this will be to a turbine manufacturer that has firm plans to invest in the Scottish offshore wind supply chain.