The most enjoyable aspects of Finding Nemo, for me, were the Australian references. The Aussie accents and personalities, the animated shots of Sydney, the depictions of marine life on the reef...they brought my sabbatical back to the front of my mind. The animators seemed to be striving for realism, and after a dozen or so scuba dives, I can attest to the realism of several details. Anything underwater appears less colorful than it does above water (because water absorbs lots of blue light, if I recall correctly). The Pixar folks nailed that. As you descend, or as day turns to night, everything under water loses its color, and several shots in the movie illustrated that effect. The young turtle who gives Marlin and Dory the pep talk before they get ejected from the current? "Alright, everyone, you're going to have a great jump today." That was every extreme sport operator I met in New Zealand.
The little cleaning shrimp (I saw a few while scuba diving)? He was hilarious, too.
"No cleaning!"
"I am so ashamed."