Today’s offshore wind farms are typically less than 25km offshore in relatively benign sea conditions and consist of up to 100 turbines. Maintenance is possible in boats about 90% of the time when wave heights are up to about 1.5m. Round 3 wind farms will be as far as 300km offshore in rougher sea conditions and may consist of as many as 2,500 turbines. At these sites, today’s access systems would only allow transfers about 210 days a year. The aim of the competition was to find concepts that can make transfers possible for a minimum of 300 days a year at a significant wave height of 3m.