According to our data division, Windpower Intelligence, worldwide offshore wind capacity stood at 14,603MW at the mid-point of the year. Which, to put into some kind of perspective, is less than 70% of the onshore wind capacity in Texas alone, and represents just under 3% of the worldwide wind power fleet.
Nor can offshore wind really be described as a global energy sector while nine tenths of it is deployed in one small patch of sea in northern Europe.
None of that will change very much over the next few years. Growth will remain incremental rather than exponential, and largely concentrated on the North and Baltic seas.
Europe will have close to 25GW of offshore wind by the end of 2020, forecasts WindEurope, and that will still account for the overwhelming majority of worldwide capacity.
China has long since abandoned its 10GW target for offshore wind by the end of this decade. Whether it will reach even 5GW is open to question. There are big hopes - and some big plans for the future of the sector in the US, but they remain some years away from fulfilment.
Growth in Europe is constrained by grid bottlenecks and overcapacity, though developers are pinning their hopes on transmission-line improvements and the retirement of coal and nuclear capacity for their post-2020 plans.
But the current and short-term growth outlook doesn't look large enough to sustain the economies-of-scale projections that were the subject of much discussion in London.
The design and development costs of 10MW-plus turbine, plus their foundations and associated infrastructure, are not justified by countries adding two or three gigawatts a year to keep their renewable-energy targets on track.
Onshore wind's expansion was built on the small-and-steady improvement principle, but the costs and complexity of offshore development demand a different approach.
The potential is huge, but it will not begin to be realised until more of the world's major players start throwing their industrial weight behind it.
Northern Europe has done the heavy lifting, and proven that offshore wind can play a cost-competitive role in electricity production. Now it requires the likes of the US, China, India and Japan to make offshore wind a truly global industry.