How do I build Underwater?

[Morjimoi]

See the title. I don't understand how I'm supposed to build underwater. I've got buildings that have the life support and everything set up for the design but it still tells me the location is underwater despite it shouldn't be an issue.

[Deantwo]

When building underwater (or any liquid sea) it has to be deep enough that the building does not breach the surface of the sea. This means that you cannot build buildings in shallow water, you have to raise the land up or make it deeper.

Aside from that, it is possible that the recent addition of drilling rigs have introduced some bugs.