English ship Swan ( 1641 ) The Swan was a 200 ton warship of the English Royal Navy , launched in 1641 . She was the last ship to be built for Charles I . She carried a number of iron cannons , which were cast by John Browne . The warship was a part of Oliver Cromwell ' s fleet of six vessels which attacked a Royalist stronghold at Duart Castle in Mull , UK , during the English Civil War , but it sank on 13 September 1653 off the west coast of Scotland due to a severe storm . A naval diver found the remnants of the Swan in 1979 and important items from the wreck were recovered during the 1990s in an excavation led by maritime archaeologist Colin Martin from the University of St Andrews in Fife , Scotland . Items recovered at that time included a corroded pocket watch which appeared to look like " . . . little more than a lump of rock from the outside " , many silver coin s , iron guns and other military artifacts . The items were deposited with the National Museum of Scotland . History . Capture . In 1645 , whilst anchored at Dublin , and with " Swan ' s " captain absent from the ship , the disgruntled crew were persuaded by the captain of a Parliamentary frigate to change sides upon promise of payment of wages regularly . Thus the ship became part of the Cromwellian fleet . Sinking . In September 1653 , a Cromwellian task force anchored off Duart Castle , a staunch Royalist stronghold of the Maclean ' s , who had already fled to Tiree . On 13 September 1653 , a violent storm blew up from the north west , which resulted in two commandeered merchantmen , the " Martha and Margaret " of Ipswich and the " Speedwell " of Kings Lynn being sunk , along with " Swan " . The wreck of " Swan " was discovered in 1979 . Recovered artifacts . Cannon . In 2003 , one of the cannons from the ship was recovered . It turned out to be an iron ' Drake ' cast by John Browne , and is believed to be the only survivor of this type of cannon . It has a mass of 3 cwt 2 qtrs 23 lb , or , and had a 3½ " ( 89mm ) muzzle and fired shot weighing . Another ship of the era , , had bronze cannons that were also cast by Browne . Watch . A barely recognizable , severely corroded and barnacle - covered pocket watch was recovered from the wreck in 1979 . It was transferred to the National Museum of Scotland , where researchers Lore Troalen , Darren Cox and Theo Skinner decided to try to analyze the watch ' s interior components by utilizing a state - of - the - art computed tomography ( CT ) X - ray scanner , originally developed by X - Tek Systems of Tring , Hertfordshire , U . K . The same type of CT scanner had been previously used to create a finely detailed 3D virtual reconstruction of the Greek Antikythera Mechanism recovered from the 2 , 200 year old sunken Antikythera wreck in the Aegean Sea . Imaging from the CT scans of the watch was used to produce equally fine - detailed three dimensional views of its interior , depicting beautifully preserved delicate brass components which included cogwheels , studs , pins , Egyptian - style pillars supporting the watch ' s top and bottom plates , as well as the watchmaker ' s personal identification ( Niccholas Higginson of Chancery Lane in Westminster , London ) . Among the decorative markings discerned were floral designs engraved on some of its parts , plus Roman numerals and fleur - de - lis on its watchface , with an English rose at its centre . Television programme . The story of the ship was featured in Channel 4 ' s programme " Wreck Detectives " . References . Citations