Spanish ship Nuestra Señora de la Santísima Trinidad The Santísima Trinidad ( officially named " Santísima Trinidad " by Royal Order on 12 March 1768 , nicknamed " La Real " and sometimes confused with the Manila galleon " Santísima Trinidad y Nuestra Señora del Buen Fin " ) was a Spanish first - rate ship of the line of 112 guns , which was increased in 1795 – 96 to 130 guns by closing in the spar deck between the quarterdeck and forecastle , and around 1802 to 140 guns , thus creating what was in effect a continuous fourth gundeck although the extra guns added were actually relatively small . She was the heaviest - armed ship in the world when rebuilt , and bore the most guns of any ship of the line outfitted in the Age of Sail . Design & construction . She was built at Havana , Cuba , to a design by Irish naval architect Matthew Mullan ( domiciled in Spain under the name Mateo Mullán ) and launched in 1769 as an 112 - gun three - decker ( some sources say 116 or even 120 guns ) . She was considerably larger than her British contemporary " Victory " and somewhat bigger than the French " Bretagne " . There is no complete plan of the ship in existence , but there are of the 112 - gun ship from 1765 , from which the original dimensions of the ship may be found . Here , the units of length are the Spanish Burgos foot ( 27 . 86 cm ) and the SI metre ( 100 cm ) , respectively : length = 213 ( 59 . 53 ) ; keel = 182 ( 50 . 82 ) ; beam = 57 ( 16 . 09 ) ; draught = 28 ( 8 . 06 ) . In 1795 , her forecastle was joined to her quarterdeck to create a fourth deck containing a battery of eight pounder guns , giving her a total of 140 guns . Her armament seems to have been quickly reduced to 130 from 136 guns , but she still carried more guns than any other ship of her time . As the only ship with four gun decks , she was reputed to be the largest warship in the world , for which she was nicknamed " El Escorial de los mares " by the Spanish , until surpassed in sheer size by the new type French 120 - gun ships such as the " Océan " ( 1790 ) and " Orient " ( 1791 ) . The weight of the additional guns , so high above her waterline , made her sail poorly , leading to her nickname , " El Ponderoso " . It was even suggested by some naval officers that she should be restricted to defending the Bay of Cádiz . " Santísima Trinidad " remains famous as one of the few four - decker ships of the line ever built . The U . S . Navy constructed the four - deck , 136 - gun and the 120 - gun French - " Valmy " ( both with similar flush deck arrangement ) , and the Royal Navy planned — but did not actually build — the proper 170 - gun four - decker " Duke of Kent " . Service . In July 1779 , Spain declared war on Great Britain , joining France in support of the American colonists in the American War of Independence . " Santísima Trinidad " became the flagship of the Spanish fleet , taking part in the Franco - Spanish operations in the English Channel in the late summer of that year . In August 1780 she took part in the capture of 55 ships from a British convoy of 63 , escorted by the ship of the line HMS " Ramillies " and three frigates . In 1782 she was incorporated into the Mediterranean Squadron , participating in the second siege of Gibraltar and she fought in the brief and indecisive Battle of Cape Spartel . In 1795 , she was modified by the addition of extra 8 - pounder guns on a new deck between her forecastle and quarterdeck . In 1797 , she was the flagship of Teniente General José de Córdoba y Ramos , the Spanish commander , at Battle of Cape St Vincent on 14 February 1797 , where she was badly damaged and nearly captured by the British fleet . She was first in action with the British ship " Captain " ( 74 ) , commanded by Commodore Nelson , and " Culloden " ( 74 ) . She was then attacked by the " Blenheim " ( 90 ) , " Orion " ( 74 ) , " Irresistible " ( 74 ) and " Excellent " ( 74 ) . By now she was severely damaged , having lost all her masts and with half of her crew killed or wounded . She struck her colours , but the British failed to take possession and she was saved by the " Pelayo " ( 74 ) and " Príncipe de Asturias " ( 112 ) . Several days later , " Santísima Trinidad " was spotted , still damaged , making her way back to Spain , and engaged by the 32 - gun frigate under Captain Richard Bowen , but she escaped . She eventually returned to Cadiz for repairs . Eight years later , commanded by Francisco Javier Uriarte and Rear Admiral Baltasar Hidalgo de Cisneros , she took part in the Battle of Trafalgar on October 21 , 1805 , as part of the combined Franco - Spanish fleet . Due to her great bulk , her helm was unresponsive in the light winds of the day , contributing to her ineffective service of the combined fleet ' s cause . Her great size and position immediately ahead of the fleet flagship " Bucentaure " made her a target for the British fleet , and she came under concentrated attack by several ships . She lost her mast and eventually surrendered to the " Neptune " , commanded by Captain Thomas Fremantle . She was taken in tow by the " Prince " , but sank in a storm the day after the battle having been scuttled by her British captors . It ' s believed that her wreck was accidentally found during testing of a new sidescan sonar of the Spanish Navy , in 2009 . Replicas . A full - size representation of the " Santísima Trinidad " can be seen and visited in the harbour of Alicante , in Spain . In 2006 a merchant ship was fitted to mimic the appearance of the " Santísima Trinidad " , therefore not being a true replica . The conversion was begun in Galicia , where the original steel hull was given a first coating of fake wood strakes and erection of the masts . Stern galleries , the deck furniture and the rigging were made in Algeciras . Finally the boat was towed to be moored in the port of Malaga , where she was used as a floating restaurant , nightclub and showroom . The original engine was retained , and the boat is able to cruise around the vicinity of Malaga for recreation purposes . A non - profit non - governmental Canadian association , the Friends of Santísima Trinidad , is assisting the Office of the Historian of the City of Havana , Cuba with the construction of a new 1 : 25 four - metre - long scale model of " La Santísima Trinidad " . Interior construction details will be exposed on one side of the vessel , and visitors will be able to use a computer interface and touch screen to take a virtual tour of the ship in Spanish , English , and French . The model will be displayed in the Naval Museum of La Habana , opened in June 2008 at Castillo de la Real Fuerza , the oldest building in Cuba and the oldest stone fortress in the New World .