Putting it under the sea is dumb, any issues that leak goes into the ocean, and it's now a lot more difficult to do maintenence plus costs to build are higher.
China thinks undersea data center are great solution.
Cheap cooling. Cheap Land, No rates & taxes, natural security, no "building", just sealed modular containers.
May 2026:
Located off the coast of Shanghai's Lingang Special Area, the $226 million data center, China’s “world's first” offshore wind-powered underwater data center (UDC) began operations in May 2026. The project, officially launched in June 2025 and completed in October 2025, hit full commercial operation in May 2026, after successful initial trials in February 2025.