I'm thinking that's a ferry crossing and they're using the ferry cable and winch to pull the tractor across. It looks to me like there could be a hidden winch in that clump of brush on the other side. The cable is out of sight on the bottom of the river.

You're right though - internal combustion engines need air, and lots of it, to run as well as a way to discharge the exhaust gases. All our machines here quit when they're submerged.