Sony F-717 digital
It is harder than you might think to get decent photos of Atlantic Bottlenose Dolphins (Tursiops truncatus). It's far worse with a digital camera that has a significant shutter delay. They stay mostly submerged, but when they surface, they usually do so in a brief looping motion that takes less than a second, and of course the part that you want to photograph, which is the face and eyes, appears and disappears first. Not to mention that they follow no particular pattern so even anticipating their surfacing is difficult. I've tossed a lot of wasted frames.
But what I initially believed to be a missed shot actually has a nice mood to it with a slight change in cropping. The shine of early morning sunlight on the water helps the idea.
By the way, hearing a dolphin squeak and click underwater for the first time while snorkeling is a very cool experience.
Note added 2012: While boosting the size of some of these images for the website update, I discovered that this was one of the collection of images that I lost when a hard-drive failed (it died, as irony would have it, when I was in the process of replacing my backup drive.) It doesn't seem to matter how many images I have that are better than this, I'm still annoyed at losing something I intended to keep.