On: Stacking concrete blocks is a surprisingly efficie...

[Const-me]

> I'm not aware of any large structures that are anchored to the sea floor in a way that resists an upward force rather than a downwards one

Marine vessels can be very large and helical screws are widely used, here’s an example https://helixmooring.com/square-shaft-anchors-2/

> even if they do fall there's nothing to damage beyond the energy storage installation.

Very expensive installation. Maybe they don’t need the reliability of bridges but they need to be able to withstand any weather.