Grebe

Hi Today i was Up at St Aidens watching a black and white grebe it had distinctive white cheeks and its lower body was white to the water. I know it wasnt a great crested and I know it wasnt a little grebe but Im not expert enough to name it. I just wondered if anyone else had been up there and seen this black and white grebe My guess is winter plumage Black necked grebe but it also looked like a Slavonian but they are too rare for here arnt they? Sorry no camera with me. Anyway maybe somebody will confirm the sighting for me. Thanks