Juvenile Blue or Grey Heron?

I was hoping to see a kingfisher from the boat this morning. We did, flashing turquoise across the channel, too quick to photograph. This young heron (well, I think it is) was watching us and he stayed on his perch while we passed by. I have only ever seen very young herons, all straggly in their nests, or adults, previously. There are no photos that I can find on the web of a similar stage of development so maybe I am wrong and this is not a heron!

PS. a Black Crowned Night Heron seems to fit him better, thanks Chamaeleo! latin name - Bihoreau gris