Bailey first appears when he hears Destiny and Dory talking to each other by telling the two to keep it quiet. Destiny explains to Dory that her neighbor Bailey, the white beluga whale, is brought in with a head injury who thinks his echolocation ability does not function properly, despite not having a thing wrong with him. When Dory tells Destiny to know what echolocation is, she explains that Bailey's ability helps find objects far away as explains to her that Bailey is "healing".
As Dory, Bailey, and Destiny talk about echolocation, Hank suddenly jumps into the exhibit and finds Dory and tells her to give him the tag given by Marine Life Institute volunteers to bring him to a permanent aquarium rather than releasing him back to the ocean again. When Dory tells Hank as she forgets to know the exhibits where her parents would be at, Destiny and Bailey tell Dory that they would be in the Open Ocean exhibit. Upon reaching the surface, Dory tells Destiny, Bailey, and Hank to find a plan how to get to the Open Ocean exhibit. Destiny and Bailey are seen again planning to help Dory and Hank find a way to get to the Open Ocean exhibit; Bailey tells Destiny to do a big splash in order to do the signal to reach the Open Ocean exhibit safely and after Destiny does a big splash, Hank tells him that this is the signal to get to the Open Ocean exhibit as he tells her to follow the signs leading to the Open Ocean exhibit.
Destiny and Bailey are seen again when they hear Dory through the pipes who is looking for her parents in the quarantine area of the Marine Life Institute while Destiny tells Bailey to use his echolocation to help Dory find her missing parents in which Bailey says that his echolocation couldn't function properly as Destiny tells him to use his ability harder. Upon using his echolocation, Destiny tells Bailey to use it harder to help Dory reach the quarantine area of the Institute and upon using the echolocation harder, Bailey tells Destiny that he sees the quarantine area through his ability of echolocation as well as Dory through the pipes. Upon using the echolocation, Destiny tells him to continue using this again to help Dory reach the quarantine area (seen in his mind of echolocation) as he and Destiny tell Dory to listen to them by choosing the said directions to help find her parents in which Bailey tells Destiny that two fish (Nemo and Marlin) are swimming from the other directions in the pipe. Worried that he saw the fish coming from this direction, Destiny tells Dory to swim the other direction to avoid colliding into Nemo and Marlin, confusing Dory as she meets up with Marlin and Nemo, confusing Dory as she meets up with Marlin and Nemo. Bailey is worried as he thought that she collided with the two fish, in which he and Destiny did not see the two clownfish at first. Destiny and Bailey found out that Dory is safe when she encountered Nemo and Marlin.
After Dory found Jenny and Charlie in the kelp forest of Morro Bay, she then tells Destiny and Bailey that she found her parents. Bailey convinces Destiny to make a plan to jump in order to reach Dory and her parents. As the two hear Dory, they manage to escape their exhibits by jumping into the ocean. As Dory, Charlie, Jenny, Destiny, and Bailey plan to stop the truck containing Marlin and Nemo inside, Bailey explains to Dory that her friends Marlin and Nemo are still in the truck as he sees some otters; he suddenly crashes into a pole as Destiny crashes into him. Dory explains to her parents, Destiny, and Bailey that the only way to stop the truck is to bring a bunch of otters, which can distract passengers upon seeing their adorable expressions. As Dory tells her parents that she would be safe, while Bailey tells Destiny to flip Dory when the otters arrive to the road in which Destiny flips Dory over the bridge as the otters carry her safely as she tells the otters to stop the passengers with their ability to cuddle with each other. Destiny and Bailey are later surprised that the truck (still with Dory, Nemo, and Marlin inside) went away. Destiny and Bailey later see the truck falling into the ocean, freeing all the fish from the truck. During the epilogue, he, along with Destiny and Hank, help tutor Mr. Ray's class.