HMS Magnificent ( 1767 ) HMS " Magnificent " was a 74 - gun third - rate ship of the line of the Royal Navy , launched on 20 July 1767 at Deptford Dockyard . She was one of the built to update the Navy and replace ships lost following the Seven Years ' War . She served through two wars before her loss during blockade duty off the French coast . On 21 December 1779 , HMS " Magnificent " with the 74 - gun ships and , and the 64 - gun under Rear - Admiral Joshua Rowley , fell in with the 32 - gun French frigates " Fortunee " and " Blanche " and the 28 - gun " Elise " , when off Guadeloupe . The French ships were in bad order ; their crews were excessively weak ; and thus they could not escape the vastly superior British force . The " Blanche " was overtaken and captured on the evening of the 21st ; the " Fortunes " , by throwing her quarter - deck guns overboard , kept away a little longer , but was captured at last in the early morning of 22 December , an hour before the " Elise " . Her war service in the American War of Independence was conducted with Rodney ' s fleet in the Caribbean , where she served in the battles off Grenada in 1779 , Martinique in 1780 and the Saintes in 1782 . Her duties during the Napoleonic Wars mainly consisted of blockade duties off the French coast , but between 1798 and 1800 , the ship had received a complete overhaul designed to extend her service life and improve her ability at performing the close blockade . " Magnificent " came under the command of Captain John Giffard on 23 February 1801 upon his transfer from " HMS Active " . On 9 April 1802 , the 8th West India Regiment revolted in Dominica . They killed three officers , imprisoned the others and took over Fort Shirley . On the following day , " HMS Magnificent " , which was anchored in Prince Rupert ' s Bay under Captain John Giffard ' s command sent a party of marines ashore to restore order . The mutineers fired upon the " Magnificent " with no effect . On 12 April , Governor Cochrane entered Fort Shirley with the Royal Scots Regiment and the 68th Regiment of Foot . The rebels were drawn up on the Upper Battery of Fort Shirley with three of their officers as prisoners and presented arms to the other troops . They obeyed Cochrane ' s command to ground their arms but refused his order to step forward . The mutineers picked up their arms and fired a volley . Shots were returned , followed by a bayonet charge that broke their ranks and a close range fire fight ensued . Those mutineers who tried to escape over the precipice to the sea were exposed to grape - shot and canister fire from " Magnificent " . The 74 - gun , the frigate , and the sloop assisted " Magnificent " , also supplying marines . On the morning of the 25 March 1804 , during her duties blockading the French port of Brest , she struck an uncharted reef close to the Black Rocks that bordered the port and rapidly began to founder . The remaining ships of the blockading squadron closed in and removed most of the crew , the remainder of whom took to boats as the ship sank at 10 . 30am , just an hour and a half after she struck the reef . Although all her crew survived , a boat carrying 86 men became diverted from the main group and was washed ashore on the French coast , where the men remained in captivity for ten years . The captain , William Jervis , was later reported to have lost £1500 in lost property on board the wreck . References . Royal Navy History