[lokopodium]

Is there a benefit over just putting it in a boat/coastal building and using water (perhaps pumped from some depth) for cooling?

[kwhitefoot]

Boats in that part of the world are subject to severe stresses because of the weather. And boats are always moving, even in harbour. Just maintaining a reliable cable connection to a boat is more challenging than connecting to a subsea container. Placing the container on the sea floor avoids almost all of the weather related problems.

[Steltek]

Microwave links? How about an oil derrick style thing mounted directly to the seabed so it doesn't move?

There's also plenty of coastline away from major cities. Find enough open space and it becomes feasibly multi-tenant. Add wind/solar and run a cable (or 3).

[mariuolo]

The closest thing I remember is Google taking over an old paper mill in Finland that used a condenser sunk into a canal connected to the Baltic sea.

https://www.wired.com/2012/01/google-finland/ there should be a video with the details here.

[brunnsbe]

There's also a data center in Helsinki, Finland that is cooled by sea water and the waste heat produced is piped via a heat pump into the district heating network. Here's a press release from 2011: http://www.investineu.com/content/atos-builds-world%E2%80%99...

[fowie]

Putting in on/in a boat or near the coast might get you the seawater for cooling, but the project lists a few other big benefits like oxygen-free atmosphere, constant temperatures year-round, and ease of deployment.

[Steltek]

A hermetically sealed capsule can be placed on a boat just as easily as a submarine, if not easier due to the pressure difference.

I'll give you the constant temperature but this project is about using the nearly-free ocean to maintain temperature so surely the delta isn't too large here.

I don't see how this is easier than a boat at anchor.