This image was taken in the Brazilian Pantanal. There were lots of yacare caimans in the shallows of this river. I saw one sink suddenly, and looked for the best location to photograph when it resurfaced. The whole thing lasted for a fraction of a second.
Nikon D4, Nikon AF-S 80-400mm f/4.5-5.6D ED VR, 1/4000 sec, f/6.3, ISO2800