A Tall Story is a magazine story.
Thomas and BoCo arrive at Brendam Docks to collect some goods from the Mainland. They are surprised to see a strange vessel moored at the dockside. Cranky watches too as the vessel slips away into deeper water. Everyone watches in amazement as the strange object then sinks. Just then, Salty arrives and tells everyone that they mustn't worry as the strange vessel is actually a submarine. The submarine is going to be used as a tourist attraction, taking visitors on underwater trips around the coast. BoCo is amazed; a boat that can travel underwater, now he's seen everything. Salty thinks the submarine is nothing and starts to tell the engines about the time a whale jumped over him. Salty tells his tales all day until Thomas, BoCo and Cranky are feeling rather fed up. That night, in the engine shed, Salty keeps BoCo and Thomas awake with more tales from the sea.
The next morning, Thomas and BoCo arrive in the yard with lots of visitors who they have brought to see an exciting event. Then, Salty appears looking very tired. Salty asks what everyone is doing in the dockyard. Thomas tells Salty that they've come to see a man jump into the sea and then spring back out again. Salty doesn't believe a word of it. Then, Salty sees Cranky use his hook to lift up a man on a platform. Then, everyone watches as the man jumps into the sea. The man touches the water and then springs back up onto the platform. Cranky says that the man is fixed to a long rope made of elastic. BoCo tells Salty that the man is doing a bungee jump for charity. Thomas then says that a submarine can't go up and down as fast as the man did. For once, Salty is completely lost for words.