No, you're insane. You can't speak whale.
4 seconds sound clip from the Finding Nemo movie soundboard.
You can hear this line at 01:10:01 in the Blu-ray version of the movie.
Quote context
[...]
- We're in a whale. Don't you get it?
- A whale?
- A whale! 'Cause you had to ask for help. And now we're stuck here.
- A whale? You know, I speak whale.
- No, you're insane. You can't speak whale.
- I have to get out. I have to find my son. I have to tell him how old sea turtles are!
- There, there. It's all right. It'll be okay.
[...]