When you are racing dory, jump on a jellyfish and push square. keep
pushing square. if you push it too late or too early, the jellyfish will
spit you out. by jumping on the jellyfish, you are getting all of the
speed rings. once you are in front of Dory, and you have reached the end
of the race, start swimming. (you can press the square button for extra
speed boosts). do this on both of the races.