I think it's just like a series of little cups inside, that gets submerged and filled, and then emptied and record the highest point.

I had been told that it was a flood gauge, I think it was from a council officer in Natural Areas, and I know what a lot of Urban Utilities infrastructure looks like.

China can already detect all subs in the South China Sea between their network of underwater sensors and synthetic aperture radar satellites.

It's a flood gauge, it's a very simple gauge, they check it after a flood occurs.

Last I heard from someone who works on it, they were aiming for March '26