Sweet was born in
Portsea, a few km inland from
Portsmouth, Hampshire, and had only a basic education. In 1844 Sweet joined the
Royal Navy at age nineteen, serving on the China Station until 1849. Sweet gained command of the merchant ship Pizarro in 1857 for which he kept the meteorological log for the
Board of Trade for several years. These efforts resulted in Sweet being awarded "Letters of Honorable Mentions". In 1861 Sweet travelled the South American waters carrying out surveys for the charts of the British Admiralty. He married in Portsea and had several children in England. In 1864 Sweet and his family arrived in
Queensland, Australia to grow cotton having migrated from England on the
Flying Cloud. In 1866 Sweet set up his first photographic practice in partnership with William Gibson. From this time Sweet committed himself to photography and in 1868 applied for the role of the official photographer for the Goyder Northern Territory Expedition, however was instead appointed as Commander of the Government Schooner
Gulnare which supported the Goyder Expedition and the new settlement at
Port Darwin. Whilst Sweet was never the official photographer of this trip (Joseph Brooks was the appointee), Sweet did take on some of Brooks' photographic duties while he was busy surveying. As a result of this, during his return from the North Sweet organised exhibitions and lectures of his views surrounding the trip and secured sales of his prints through James Williams's Stationery shop. In 1870 Sweet was also commissioned to supply northern construction teams who were building the British-Australian overland telegraph link from Darwin to
Port Adelaide. Sweet's views are the only record of this event. At this time he was also commissioned to survey the
Roper River. Sweet made five voyages between Adelaide and the Northern Territory between 1869 and 1872, taking photographs alongside managing his main duties.
Schooner Gulnare Previously a slaver in the Caribbean, the 150-ton two-masted schooner was purchased by the South Australian Government in 1869 and refurbished as the Northern Territory supply vessel, replacing
Sea Ripple, which had been condemned as unfit for service. Within a few weeks Sweet had been appointed her commander and left for the Northern Territory. In 1870
Gulnare took the first Government Resident,
Bloomfield Douglas, to Port Darwin. She then acted as a Goyder's supply ship. Sweet stayed on as captain and H. R. Marsh, later captain of
Flying Cloud, was mate. ;The wreck
Gulnare, under Captain Sweet, left
Darwin Harbour for the
Roper River at 7am on 5 October 1871, and that same night she ran aground on one of the reefs that surround the
Vernon Islands. The
Bengal under Captain Hummel set out from Darwin to render assistance on the 10th, and after removing twenty tons of cargo assisted in dragging Gulnare free, and returned to Darwin on the 13th. Gulnare returned to Darwin on the 14th and run onto the beach to have her hull inspected. At an inquiry on 19 October Sweet testified that he was confident that
Gulnare was sufficiently seaworthy to return to Adelaide, but the crew had deserted her to work on the
Overland Telegraph Line. Sweet insisted that
Gulnare could be repaired in a week at most, and could profitably make a return voyage to Adelaide, but she was deemed unseaworthy and abandoned. The Darwin enquiry had no authority to judge Sweet's actions, and at a properly constituted Court of Enquiry held at Port Adelaide on 25 and 26 July 1872, Sweet was found to have been lacking in judgment and censured, but his certificate of competency was returned to him, but he lost his government commission. He then captained the barque
Wallaroo, transporting coal from
Newcastle to South Australia. On 11 May 1875
Wallaroo became grounded on Office Beach,
Wallaroo during a gale. An inquest attributed the grounding to Sweet's miscalculation, and he was censured for neglect, but again did not lose his ticket. Sweet had already resigned his position with the
Black Diamond Line; he retired from the sea and opened a photographic studio in Adelaide, ==Photography==