I started by shooting gulls that were sitting in the water, bobbing in the waves. Once, I saw one dive to hunt for something, but I saw no sign of a catch.
I did get to practice follow-focusing on birds in flight, in tricky conditions, between the rain and mist, resulting dim light, and backgrounds that sometimes were more contrasty than my subjects.
This is what the lens looked like when I was done. I had already dried off the camera body when I thought to get an iPhone snap of the drenched telephoto.