Microsoft Corporation has just retrieved its Project Natick data center from the seafloor off Scotland’s Orkney Islands after two years of deployment.

In 2018, the company sunk this shipping-container-size data center into the ocean, loaded with 12 racks containing a total of 864 servers and associated cooling system infrastructure. Project Natick’s 40-foot long Northern Isles datacenter was assembled and tested in France and shipped to Scotland where it was attached to a ballast-filled triangular base for deployment on the seabed.

The Northern Isles underwater datacenter was manufactured by Naval Group and its subsidiary Naval Energies, experts in naval defense and marine renewable energy. Green Marine, an Orkney Island-based firm, supported Naval Group and Microsoft on the deployment, maintenance, monitoring and retrieval of the datacenter, which Microsoft’s Special Projects team operated for two years.

Microsoft’s research team hypothesized that a sealed container on the ocean floor could provide ways to improve the overall reliability of data centers due to less corrosion from oxygen and humidity, temperature stability and zero disturbances from maintenance workers.

According to the company, this retrieval launches the final phase of its years-long effort, proving that the concept of underwater datacenters is feasible, as well as logistically, environmentally and economically practical. This Project Natick’s datacenter is Microsoft’s second trial deployment of underwater data centers, having submerged a smaller system for three months in 2016.

“We are now at the point of trying to harness what we have done as opposed to feeling the need to go and prove out some more. We have done what we need to do. Natick is a key building block for the company to use if it is appropriate,” said Ben Cutler, a project manager in Microsoft’s Special Projects research group who leads Project Natick.

Coated in algae, barnacles and sea anemones, the data center was power washed by the Green Marine team and moved to Global Energy Group’s Nigg Energy Park facility in the North of Scotland. There, Naval Group opened the facility and slid out the server racks while Microsoft research team collected components including failed servers and related cables to send to Redmond for analysis, with the hope of getting more explanations to the perceived submerged hardware benefits.