Tom Swift and His Submarine Boat; Or, Under the Ocean for Sunken Treasure

A resourceful young inventor builds a pioneering submarine and outfits it and other inventive craft for a deep-sea expedition to recover sunken treasure. The plot follows the technical finishing of the submersible, preparations and trials, confrontations with jealous rivals and suspicious antagonists, an episode of imprisonment, hazardous underwater work in diving suits, attacks by sharks and hostile parties, and the use of experimental devices such as an electric projectile and strategic ramming to secure a wreck. Action-driven chapters alternate with problem-solving scenes that emphasize mechanical ingenuity, courage under pressure, and the risks of salvage beneath the waves.