Great Crested Grebe

A few Saturdays ago whilst running round Pitville Lake as part of the Cheltenham Parkrun, I spotted a grebe.  Today, after completing, I walked the course and found it again.  It was a bit difficult to snap as it swam across the lake as I approached, making me have to go round to the other side (more exercise!), and then it dived and disappeared from sight.  I believe that it is a great crested grebe.