Seizure of the Norfolk
The Norfolk was built at Norfolk Island in 1798 when John Townson of the New South Corps was Lieutenant-Governor.
John Townson had transferred to the New South Wales Corps in October 1789. He arrived in the colony in the Scarborough in June 1790. Most of his military service in the colony was spent on Norfolk Island, where he was stationed for over six years between late 1791 and late 1799. He was a member of the court of inquiry in 1794 which investigated Lieutenant-Governor Philip Gidley King's actions during the mutiny on the island the previous year. In May 1795 he was promoted captain and from September 1796 until November 1799 acted as lieutenant-governor of Norfolk Island while King was absent in England. 
FIRST VOYAGE TO PORT JACKSON
The Norfolk was a vessel of 25 tons burthen. She completed her first voyage to Port Jackson on the 15th June 1798.
During his administration Governor Hunter gave every possible encouragement to exploration. He despatched John Wilson on two expeditions into the country to the south of Picton in January and March, 1798. In the previous November, he equipped and manned a whaleboat for the use of Surgeon Bass in exploring the south coast; during this expedition Western Port was discovered and the existence of Bass Strait was established.
VOYAGE TO THE SOUTH
In December 1798 Lieutenant Flinders and Surgeon Bass were sent in the Norfolk to make further explorations to the south, and in this voyage the circumnavigation of Tasmania was accomplished. 
Select here to read of the voyage of the Norfolk 
With a Captain and crew of five, the Norfolk was then used to carry provisions and grain to and from the Hawkesbury River. She was included in the list of floating craft belonging to Government in September 1800.
SEIZURE OF THE NORFOLK
Following is an extract from H.W.H. Huntington's The History of Newcastle.....
In November, 1800, Governor King was much concerned to hear of the piratical seizure of the Government decked boat Norfolk, of 25 ton, laden with 500 bushels of wheat, by a gang of 15 desperate convicts, who had boarded her in Broken Bay on her voyage to Port Jackson from the Hawkesbury in October. The runaways proposed proceeding to the Dutch settlements among the Moluccas, and on their voyage there they called in at the Hunter River, where their vessel was driven on shore, and they seized a small vessel belonging to one of the Sydney traders.
Immediately the piratical transaction was reported to the Governor he issued a general order, bearing date 9th November, 1800, wherein he set forth that "in consequence of the daring seizure of the Norfolk sloop by a party of convicts in the Hawkesbury, no boats or decked vessels are to sail from hence to the Hawkesbury, or from thence to this place, without giving three days' notice to the Governor or officer in command at those places, and to wait for two or three other vessels going at a time. Should any future attempts of that kind be made, the people belonging to those vessels are: on pain of the most exemplary punishment to cut away their masts 'and rigging before they are boarded, and, if possible, to run them ashore and bilge them, for which purpose each vessel must be provided with an axe or tomahawk."
As to the probable fate of the pirates, the order states, " On this occasion the Governor finds it necessary to fore warn any convicts from attempting such a scheme in future, as nothing but inevitable destruction awaits those who have seized the Norfolk. If they escape the almost certain dangers they have to encounter from a leaky vessel, rotten sails, no means of procuring water, and neither compass, chart, or quadrant; if they are so fortunate as to avoid the bad consequences of these wants, and dissensions among themselves, they are sure to meet their fate, not only in any British settlement, but also in their native country, the Governor being determined to inform the different Governors of his Majesty's and the company's settlements of the description of these people, and also the magistrates of the different places in England and Ireland where they were convicted."
With all speed Governor King despatched an armed boat to the Hunter River, where the Norfolk was found bilged through the unskilful handling of the pirates, who thereupon committed a fresh act of piracy by seizing another boat. The armed cutter, after a desperate chase, captured nine out of the fifteen desperadoes, and secured the Sydney trader's vessel uninjured, but the Norfolk went to pieces in the surf off the point afterwards denominated Pirates' Point, and now known as Stockton.
With respect to the Norfolk sloop pirates, they were all found guilty and sentenced to death. Two of the ringleaders were executed in the presence of the military and convicts. The other seven offenders were reprieved at the foot of the gallows, as they were in an emaciated condition from the hardships they had endured. Eventually they were ordered to serve seven years transportation on Norfolk Island. The Rev. Samuel Marsden administered spiritual consolation to the condemned men. The examples made created a solemn effect on the people, and it was generally thought that few, if any, rash attempts of the kind would be committed in the future. 
F.A. Cadell in a lecture on the Settlement and Development of Newcastle includes a few more details.....
"The history of Newcastle is one of romance," said Mr. Cadell; "The Norfolk, a boat of 25 tons used by the Government, was on its way from the Hawkesbury River with 500 bushels of wheat for Sydney and was seized at Broken Bay by 10-15 convicts. They made northward. Turning into Hunter's River, the boat was carried against a point on the north shore (now Stockton) which in consequence was called Pirate Point. Realising the necessity for expedition in quitting the port, they seized another small boat, then made for the open sea once more. Only nine of the men left in the small boat, the others probably preferring to take their chances among the natives. An armed cutter from Sydney pursued and captured the nine, who were taken back to Sydney and condemned to death. Only two of the number were executed. The others were transported to Norfolk Island.
The six who had remained behind crossed to the southern shore and set up camp in the vicinity of what is now known as Throsby Creek, subsisting on fish and meat provided by friendly natives.
The party was reinforced by two more convicts who had escaped from one of the small trading boats. After several months some of the party grew restless and weary of the primitive life in the bush. It was suggested that they return to Sydney and surrender. They were dissuaded from this course by their leader - named Grace, who appeared to be above the average in intelligence, and of a domineering character. Three of their number decided to take the risk. Two were captured, and the other died.
LIVING WITH THE ABORIGINES
The Norfolk convicts were in the vicinity of Newcastle for many months and it was on record that in 1801 one of the men was seen with the natives. Nothing further had been recorded of them, but it could be taken for granted they ended their days with the natives 
NOTES AND LINKS
1). Who was the convict named Grace mentioned above by F.A. Cadell? There were three men by the name of Grace who arrived in the colony as convicts before 1801 -
James Grace tried at Middlesex in 1784 and arrived on the Friendship in 1788 - ? Died at Norfolk Island in 1793
James Grace who was tried at Westminster and arrived on the Royal Admiral in 1792
Ismael Grace tried in Bristol 1796 arrived on the Barwell
Peter Ludlow who was pardoned after having been found guilty of felony in 1801 may have been one of the Norfolk pirates. (See State Archives NSW, Convict Registers of Conditional and Absolute Pardons, 1788-1870 Reel 775 and NSW Capital Convictions Database)
2). The tale of HM Norfolk by Mike Scanlon - Newcastle Morning Herald
3). There was also another vessel by the name of Norfolk in the colony.......The Government owned Harbinger, a brig of 56 tons was purchased by Governor King in May 1801. He renamed her the Norfolk and employed her in carrying despatches, stores etc to Norfolk Island. In November 1801 King sent her to Otaheite for a cargo of salt port, in charge of William House. While lying at anchor in Matavai Bay, being unable to ride out a heavy storm, her cable was cut, and she was allowed to drive on shore.
MORE PIRATE ESCAPES
Escape from Rosehill 1790
Escape of Mary Bryant 1791
The Cumberland 1797
Seizure of the Norfolk 1800
Field Broadbent & Johnston 1804
Pirates at Newcastle 1806
Seizure of the Harrington 1808
Pirates of the Speedwell 1814
Patrick Riley - Nautilus 1816
Convict Pirates in 1818
Seizure of the Eclipse 1825
Attempt to Seize the Gurnett 1826
Seizure of the Wellington 1827
Escape from Nobbys in 1842
Seizure of the Brothers 1844
 M. Austin, 'Townson, John (1759–1835)', Australian Dictionary of Biography, National Centre of Biography, Australian National University
 Historical Records of Australia, Series 1, vol. 2, page xvi.
 Historical Records of Australia, Series 1, vol III, p. 769
 Historical Records of New South Wales, vol. IV, p. 157
 Historical Records of New South Wales, vol. IV p. 282
 Newcastle Morning Herald, 5 October 1897. (H.W.H. Huntington)
 Newcastle Morning Herald 16 September 1939 (F.A. Cadell)