Grebe feud

We witnessed a spectacular fight today. Water splashing, wings flying, one pushing the under water. I have no idea what it was about - probably territory or mating. It went on for some time and then suddenly they were done and went about their business. Their business being courtship for one of them with the grebe you see in the back of the photo. The other went back to taking care of the young that was witnessing the fight but is just out of the frame. Oddly this one did not have a mate around. Perhaps the fight was about who got to be the mate of the remaining grebe.
What the coot is doing there I have no idea. Maybe it's their territory as well but they don't dare jump in just yet.