[dubcanada]

Salt water absolutely murders things, combined with constant movement almost anything will be torn apart in very little time. It's an extremely harsh environment compared to space, which is not anything. If you can get past the solar extremes without earths shield, it's almost perfect for computers. A vacuum, energy source available 24/7 at unlimited capacity, no dust, etc.

[h3half]

The vacuum is the problem. It might be cold but has terrible heat transfer properties. The area of radiators it would take to dissipate a data center dwarfs absolutely anything we’ve ever sent to orbit

[kakacik]

Also solar wind, cosmic rays etc. We don't have perfect shielding for that yet. Cooling would be tricky and has to be completely radiative which is very slow in space. Vacuum is a perfect insulator after all, look how thermos work.