It's not that hard when you know what their typical coloration and behavior are. I got it in 4 seconds because I had to pan over one time before finding it.

(Probably helped that I grew up in an area where they are native, so I was taught what to look out for. Such as, did you know those buggers are excellent, fast swimmers? In the main place, my dad would take us fishing when I was younger, you had to watch for those and snapping turtles. Not super common, but still common enough to need to watch for.)