the movie next shows nemo's first day of school. nemo has a tiny right fin, because his egg was injured by the barracuda attack. this makes it difficult for him to swim. after marlin embarrasses nemo during a school field trip by mistake, nemo refuses and sneaks away from the reef towards a boat. so he gets captured by scuba divers. as the boat sails away, one of the divers accidentally knocks his diving mask into the water.