The Datacenter Beneath the Sea [/ðə ˈdatasenter bɪˈniθ ðə ˈsi/] n - Project Natick was a Microsoft research effort that set a shipping-container sized datacenter on the seafloor off the Orkney Islands in Scotland. There it abode two years, then was drawn up for study. The intent was never to fill the sea with datacenters; it was to isolate a few variables and learn whether the notion deserved to be taken seriously.

Of What Was Tested

• Cooling without chillers. [/ˈkʌːlɪng ˈwɪthæʊt ˈkhɪllɛrs/] n The surrounding seawater drinks the heat. The design cast off the conventional facility cooling plant entire, and with it the water and chemicals such a plant consumes.
• A controlled atmosphere. [/ˈæ ˈkɒntrɒllɛd ˈætmɒsphɛrɛ/] n The vessel was filled with dry nitrogen and sealed. Wanting oxygen, people, and the cycling of humidity, the 864 servers failed at a reported one-eighth the rate of the equivalent land-based control group.
• Renewable power. [/ˈrɛnɛwæblɛ ˈpɒwɛr/] n The Orkney site drew on local renewable energy from the European Marine Energy Centre. The test asked outright whether the datacenter could live on variable, locally generated power.
• Lights-out operation. [/ˈlɪghtsæʊt ˈɒpɛrætɪɒn/] n Once sunk, the unit was never serviced. The design had to endure the whole mission without a human hand.

What the Sea Returned

• Reliability surprised them. [/ˈrɛlɪæbɪlɪti ˈsʌrprɪsɛd ˈthɛm/] n The sealed, nitrogen environment proved a greater reliability win than the cooling itself. If the atmosphere is the cause, the lesson travels to land.
• Deployment speed. [/ˈdɛplɒimɛnt ˈspɪːd/] n The unit was manufactured, shipped, and deployed in under 90 days. Such speed has meaning for rapid response and edge scenarios.
• Not a general answer. [/ˈnɒt ˈæ ˈgɛnɛræl ˈænswɛr/] n The economics hinge on the site, the workload, and the cost of underwater maintenance. It is a research result, not a product specification.

What Lesser Sites May Borrow

• The reliability worth of a controlled atmosphere is a hint to attend to humidity, oxygen exposure, and human-induced disturbance in existing facilities.
• A closed, modular design with no in-routine maintenance is a fair stress test for any remote or hard-to-reach site.
• The chief yield of the experiment was data. Before scaling an unusual idea, run a small, instrumented version that you can retrieve and study.

Official photos and the full report are on the Project Natick site.

See Efficient datacenter case studies for the other cases, and The Engines of the Hall for the conventional chain the experiment aimed to simplify.