Kayaks are a great way to get close to birds without spooking them. Of course it can be difficult to operate a camera while trying to maneuver your vessel, but with a little practice it's quite possible. My preferred kayak lens is the 70-200 f2.8. I can hand hold it, and shoot wide open to achieve a fast enough shutter to freeze any boat motion. I always focus on the eyes of the subject. As my photographer friend Beth Green always says, "The eyes are the window to the soul, and are therefore a critical part of the portrait". I find the same thing to be true with wildlife photography.