This is an uncropped photo of a jaguar swimming across a river in the Pantanal region of Brazil right in front of my boat. Had the cat been any closer, I wouldn't have been able to focus with the Canon 500mm f/4 telephoto I was shooting with (the minimum focusing distance is 14.5 feet). Virtually all of the prey jaguars live on -- caiman and capybara -- inhabit the river, so these cat's are powerful swimmers. Because I was hand holding a large and heavy lens, and because the boat was moving, I chose a very fast shutter speed to guarantee a sharp picture. My settings were 1/1600, f/8, and 1600 ISO. With my Canon 1Dx Mark II, I used a frame rate of 14 fps so I could capture every nuance of the movement. My AF was set to AI servo which locked the focus onto the swimming jaguar. My next photo tour to the Pantanal is Oct. 2021.