No, the water wheel ("water brake", they called it) was real, it was for wasting energy, and we didn't go anywhere; but also, yes, it was a submarine, in form, albeit not exactly in function.

If you can reveal, what sort of facility was this, and in what sector (e.g., business, research, government, military, NGO)?

or a carrier

In which case they might have mentioned the nuclear-powered slingshots.