Lucky, a small rubber duck, is born in a toy factory and destined for a store shelf, but a faulty whistle dooms him to be discarded. Driven to find a home, he squeezes back toward a box that's about to board a cargo ship for a five-week voyage. The other toys mock his flaw, yet Lucky longs for a child who will truly love him and call him their own.
At night, he searches for a safe place to rest and is initially turned away by the others, until he takes shelter on the ship’s steamer. There he befriends a timid toy turtle named Snap and a hippo with mismatched eyes named Flo, two fellow dreamers who also hope to be chosen by a loving kid. The trio forms a fragile bond as they cling to the hope of belonging somewhere.
When the ship’s captain, Captain Chase, leaves, the tub toys throw a party called the tub toy twist. A violent storm soon rocks the vessel, and in the chaos, Lucky is swept overboard and becomes separated from his friends. The next day finds the ship in disarray, with toys scattered inside their boxes, and a sense of urgency pushes the group to reunite and prove their worth to a child who will cherish them—alongside the reassuring presence of the shark toy, Shark Toy, who begins to understand his own value to the group.
Lucky awakens to new dangers when swordfish tease him, but he is rescued by Wilbur, a kindhearted seagull who volunteers to help him return to the ship. Wilbur’s aid is short-lived, however, as a stone-strewn assault by kids injures his wing, forcing Lucky to press onward alone. A mossy trail is eaten away by a telegraphed crab, leaving Lucky disoriented, but a supportive pod of dolphins lends speed and morale to his journey.
A dramatic reunion with Snap and Flo follows, and Lucky’s voyage takes another turn when a whale swallows him. With Flo’s encouragement, Snap plunges into the whale’s blowhole and frees Lucky, and the three friends make their way back to the ship with Wilbur in tow. They are soon caught in a thick mist that tests their resolve, but the memory of a brave kid helps Lucky rally the courage to guide the group toward safety. Together they strive to restore the ship’s balance as another storm approaches, aided by the dolphins during the evacuation.
Yet danger isn’t done with them. Lucky is swept away again, ending up in a shallow pool where sea reptiles mock him and he nearly loses hope. The next morning, a nearby ship answers the call, aided by Wilbur, and leads the group back to Lucky. He is finally adopted by the kid who started this journey, while the remaining tub toys find loving homes with other children, and Wilbur is invited to stay. Through it all, Lucky’s voiceover reminds us that dreams can come true.
