I was watching humpback whales' bubble net feeding from a boat. Gulls and eagles were taking advantage of the before and after herring close to the surface. The whales were due to be back up on the surface and plenty of gulls were near the surface of the water waiting.
I saw an eagle start diving and thought it was going for the herring, the same as the other birds. The eagle had the bigger game on its mind. It hit the gull, knocked it into the water, waited for the gull to take off again, grabbed it by the back, and threw it in the water again. This went on for several minutes, as it wore the gull down and finally carried it off back to its nest. This image is the back grab.[the_ad id="61677"]