This is impressive... what lens did you use for this shot?
Looked at your flickr and you have some really nice captures!
I used my Canon EF24-105mm f/4L IS USM. I used 8 in aperture. However, I would have liked to use 4. It was shot at 65mm, I was lucky the birds were flying very close to the boat
Here is 2 more bird shots from the same boat: