Isaac Peral
Spanish naval officer who designed and built the Peral submarine — launched at La Carraca on 8 September 1888, electrically propelled and torpedo-armed — which in trials fired the first torpedo launched underwater by the Spanish navy. The technical board rejected the project despite the trials, Peral left the navy, and the boat survives in the Cartagena Naval Museum.
Why this wins its question: Submarine histories jump from Holland to the world wars; the documented 1888-1890 Spanish electric boat with a live underwater torpedo launch is missing from most of them. Claims here come from the naval museum foundation that holds the actual vessel.
Claims
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The Peral submarine, designed by naval lieutenant Isaac Peral and built at the La Carraca arsenal, was launched on 8 September 1888; the Fundación Museo Naval presents it as the first electric submarine, armed with torpedoes.
In sea trials from 1889, the boat performed submerged navigation and on 20 June 1890 fired, off Cádiz, the first torpedo launched underwater by what became the Spanish navy's submarine force.
Despite the trials, the supervising technical board rejected the project amid documented ministerial obstruction; Peral left the navy, and the submarine — abandoned for years at La Carraca — was moved to Cartagena in 1929 and is preserved in the Naval Museum there after a 2012 restoration.