We've loved this ride since the first day it opened. Scratch that, since before it was even announced it was going to be there. I can remember when Finding Nemo first came out in theaters and was a smash hit, thinking that it would make the perfect ride in the (at the time) vacant lagoon in Tomorrowland at Disneyland. We watched and waited in anticipation for the ride to be completed and yes, you may have guessed it - we waited in line for 3 1/2 hours on the opening day to be some of the first people to ride it. Yes, then we went back a couple days later and waited another 3 hours. The kids loved the ride that much. It really is a cute ride, even after 3 1/2 hours of waiting in line.
It's great for families with kids of all ages (only thing to note is there is one short scene where the lights go out and there's a pretend electrical issue - this could scare some smaller children). Be prepared to climb down the very narrow curved staircase to enter the boat. There is also a non-moving special viewing area for handicapped guests.
The technology used is state of the art and is actually tough to figure out how they make certain effects work. For those curious, there are silk screens with images/videos projected on to them to give the effect of the actual characters moving around and swimming with you under water blended with actual underwater scenes.
We've now been on this ride dozens of times since it opened, but one time that stands out in my mind as just really neat was the time that the fireworks were just beginning as we were loading in to the submarines. It was a Disney Magic Moment. Riding Finding Nemo at night time is also a different experience than during the day because in the beginning, the lagoon is lit up with colorful lights and it adds to the magic of the ride.