Likely Heron but which one?

Likely Heron but which one?

Observation - Likely Heron but which one? - Southern Africa. Description: This bird was fishing in small pond, saw it get lucky with a fish but missed the shot. When it flies the undersides of the wings are white.

This bird was fishing in small pond, saw it get lucky with a fish but missed the shot. When it flies the undersides of the wings are white.