Thank you for your very thorough comment.
No this wasn't a quick point and shoot shot. I took quite a few shots whilst I was there, mostly of the cygnets as I'd never actually seen any before 'in the flesh'.
I still have so much to learn. I am gradually picking up macro shots so I'm slowly becoming more aware of the DOF. When I took this shot, a few months ago now, I wasn't really aware of it, hence the low F number.
Hope this makes sense, I've had a few too many ciders ;-)
Thanks again for your words, much appreciated.
::Please Look At The Camera:: (80) *