HMS Guardian was a 44-gun fifth-rate two-decker of the Royal Navy, later converted to carry stores. She was completed too late to take part in the American War of Independence, and instead spent several years laid up in ordinary, before finally entering service as a store and convict transport to Australia, under Lieutenant Edward Riou. In 1789 Riou sailed Guardian, loaded with provisions, animals, convicts and their overseers, to the Cape of Good Hope, where he took on more supplies. Nearly two weeks after his departure on the second leg of the journey, an iceberg was sighted and Riou sent boats to collect ice to replenish his water supplies. Before he could complete the re-provisioning, a sudden change in the weather obscured the iceberg, and Guardian collided with it while trying to pull away. She was badly damaged and in immediate danger of sinking. The crew made frantic repair attempts but to no apparent avail. Riou eventually allowed most of the crew to take to Guardian boats, but refused to leave his ship. Eventually through continuous work he and the remaining crew were able to navigate the ship, by now reduced to little more than a raft, back to the Cape, a nine-week voyage described as "almost unparalleled". Riou ran Guardian aground to prevent her sinking, but shortly afterwards a hurricane struck the coast, wrecking her. The remains were sold in 1791.
Construction and commissioning
thumb|350px|Plan of [[HMS Resistance (1782)|HMS Resistance, a sister ship of HMS Guardian. Resistance was ordered the same year and was laid down two months before HMS Guardian.]]
She was ordered from Robert Batson, Limehouse on 11 August 1780 and was laid down in December that year. Guardian was launched on 23 March 1784, too late to see service in the American War of Independence and was instead fitted out at Deptford Dockyard for ordinary. The builder was paid for her construction, with the Admiralty paying another to fit her out. After five years spent laid up she was fitted out at Woolwich in 1789 to serve as a store and convict transport, commissioning under Lieutenant Edward Riou in April.
Voyage to Australia
Riou was tasked with delivering the stores consisting of seeds, plants, farm machinery and livestock, with a total value of some , and convicts to the British settlement at Botany Bay. Also aboard Guardian was a young midshipman named Thomas Pitt, the son of politician Thomas Pitt, and nephew of Prime Minister William Pitt.
With over 300 people aboard his ship, Riou left Spithead on 8 September, and had an uneventful voyage to the Cape of Good Hope, where he arrived on 24 November and loaded more livestock and plants.
thumb|Engraving made in 1801 after Riou's death during the [[Battle of Copenhagen (1801)|Battle of Copenhagen; "Captn Edwd Riou Commander of the Guardian Frigate in the year 1789 but late of His Majesty's ship Amazon who fell gloriously in the Attack of the Danish Fleet and Batteries off Copenhagen 2 April 1801"]]
Now clear of the immediate danger of the ice, Riou found himself in a desperate situation. There was of water in the hold and more was rushing in, while the sea was rising and a gale had sprung up. The pumps were manned, but could not keep up with the ingress of water, and by midnight there was of water in the hold. At dawn on 25 December, an attempt was made to fother the hull by lowering an oakum-packed studding sail over the side to cover the gash in the hull and slow the flooding. This was temporarily successful and by 11 o'clock the pumps had been able to reduce the water to a level of . The respite was short-lived, when the sail split under the pressure of the water and the water level began to rise again. At this a number of seaman requested permission to take to the ship's boats.
thumb|The Guardian frigate, commanded by Lieutenant Riou, surrounded by Islands of Ice in the South Seas.
Riou gave the note to Mr Clements, the master of Guardian, who was given command of the launch. A total of 259 people chose to join the five boats, leaving Riou with sixty-two people: himself, three midshipmen, including Thomas Pitt, the surgeon's mate, the boatswain, carpenter, three superintendents of convicts, a daughter of one of the superintendents, thirty seamen and boys and twenty-one convicts. Guardian was nearly awash by now with of water in the hold, but a bumping noise on the deck attracted attention, and on investigation was found to be a number of casks that had broken free and were floating in the hold, trapped under the lower gun deck. Realising that this was providing extra buoyancy, Riou had the gun deck hatches sealed and caulked, while another sail was sent under the hull to control the flooding. Having now created a substitute hull out of his deck, Riou raised what little sail he could and began the long journey back to land, with the pumps being continuously manned.
thumb|The distressed situation of the crew of the Guardian Frigate
For nine weeks Riou and his small crew navigated Guardian, by now little more than a raft, across the to the Cape of Good Hope.
A gale on 12 April drove Guardian on the beach. The wreck was sold on 17 February 1791.
Aftermath
J. K. Laughton, writing in the Dictionary of National Biography, described the voyage as 'almost without parallel'. Of the boats sent out on 25 December only the launch, with 15 people, survived, having been rescued by a French merchant.