Digging in the depths?

I was astonished to see this video clip of an excavator operating off the coast in an unnamed country. It's obviously been modified to work in that environment, but I would have thought the salt water would have rapidly rusted it into uselessness. Clearly, that can't be the case.

I'd never have thought of setting up a machine on an extended base like that. I'd have looked instead to put one on a barge, and use it out of the water. Ingenious!

Peter