Embarked 150 men
Voyage 163 days
Surgeon's Journal - Yes
Master James Lindsay
Surgeon Superintendent William Evans
To Van Diemen's Land
Surgeon William Evans joined the Asia at Deptford on 28th June 1823. On the 15th July 1823, 150 male convicts were received on board from the Justitia Hulk which was moored at Woolwich. The Asia sailed for Van Diemen's Land in company with the Guildford convict ship with prisoners for New South Wales. 
The Military Guard consisted of a division of the 40th regiment under the command of Captain Bishop. One subaltern, one sergeant, two corporals, thirty men, five women and a child, embarked on the 5th July. The 40th had been serving in Ireland.
Following is an excerpt from Historical Records of the 40th (2nd Somersetshire) Regiment By Raymond Henry Raymond Smythies listing the ships that brought detachments of the 40th regiment to New South Wales in 1823 and 1824..........
Early in March 1823, the commanding officer, Lieutenant-Colonel Thornton received an intimation that it was intended to send the regiment to New South Wales. In the meantime it was ordered to proceed to Dublin, thence by sea to Liverpool, and after that by road to Chatham, in order to form guards for convict ships when required. The head quarters reached Dublin on 15th March and occupied the Royal Barracks. On the 30th the whole regiment embarked at Pigeon House, in eight small vessels, and reached Liverpool the following day.
A twenty-eight days' march, including three Sundays, brought the regiment to Chatham. The Regiment marched in three divisions; the first arrived at Chatham on 21st April; the second, consisting of two companies, halted, and remained at Deptford; and the 3rd reached Chatham on 23rd April.
During the next year the 40th was sent out, in small detachments, as guards on board convict ships to Australia. This was after several years' rough service in Ireland, and but a short period of rest in England........
Embarked 25th April 1823 on shipAlbion. Lieutenant Lowe
Embarked 5th July 1823 on shipAsiaCaptain Bishop
Embarked 10th July 1823 on shipIsabella. Lieutenant Millar
Embarked 18th July 1823 on ship Sir Godfrey Wilestoe. Captain Hibbert
Embarked 29 July 1823 on shipGuildford. Captain Thornhill
Embarked 31st July 1823 on shipMedina. Lieutenant Ganning
Embarked 5 August 1823 on shipCastle Forbes. Lt.- Col. Balfour
Embarked 29 December 1823 on shipPrince Regent. Captain Stewart
Embarked 5th February 1824 on ship Chapman. Captain Jebb
Embarked 25 February 1824 on shipCountess of Harcourt. Captain Morow
Embarked 14 June 1824 on shipMangles. Lt.- Col Thornton
Embarked 14 June 1824 on ship Princess Charlotte. Lieut Neilley
Passengers included Deputy Assistant Commissary General Fletcher and Lieut. O'Shea of the 13th Light Infantry on his way to join his regiment in Calcutta.
Departure from England
William Evans described their difficulties after leaving the Downs......From the Downs we sailed on the 9th August with beating winds down the channel and were obliged to put into Portsmouth on the 15th in consequence of the prevailing westerly gales with much rain. Sailed from Portsmouth on 28th August 1823 and the weather gradually became more settled until we reached Madeira when the sick list diminished to some trifling cases of debility arising from the long confinement of many of the prisoners in the different gaols previous to their embarkation. 
Surgeon William Evans
This was William Evans' fourth voyage as surgeon on a convict ship. He kept a Medical Journal from 28th June 1823 until 18 January 1824......
The prisoners' general health was good, though a few laboured under debility, whom notwithstanding I was induced to take as Mr. Capper wished to get them out of the country. From the continued wet weather several cases of catarrh occurred before we reached the Downs. 
They suffered unbearably hot weather between the Cape de Verde and the Islands and about twenty or thirty convicts and the Guard were permitted to sleep on deck until they reached the Equator.
During the day the prisoners were all on deck when the weather permitted and were ordered to bathe daily. Those who showed scorbutic symptoms were given lemon juice daily. The surgeon thought they were among the most slothful of the prisoners.
There were two deaths on the voyage out - William Roberts age 24 died on 4th October 1823 after suffering epileptic fits and paralysis and Thomas Nichols on 9th October 1823 after becoming ill with fever. 
Arrival in Van Diemen's Land
They had remarkably fine weather after the Equator and arrived in Van Diemen's Land on the 19th January 1824.
James Porter was born in London in about 1800. He was sent to sea at an early age and spent some time in Chile. In 1821 he was convicted of stealing and sentenced to transportation for life. He arrived in Hobart the following year on the Asia. After several attempts to escape he was sent to the penal settlement at Macquarie Harbour. In 1834, with nine other convicts, he seized the brig Frederick and sailed her to Chile. They landed at Valdivia where they assumed new identities as shipwrecked sailors. In 1836 Porter was arrested, returned to England, and transported again to Tasmania, arriving in 1837 on the Sarah. He was sentenced to death for piracy, but the sentence was commuted and he was transported to Norfolk Island. After four years of good behaviour he was transferred to the mainland. In May 1847 he absconded from Newcastle, supposedly on the brig Sir John Byng. He was never heard of again. State Library of NSW. Autobiography 1840 - 1844 written at Norfolk Island
Notes and Links
1). Convict artist Thomas Bock arrived on the Asia. Find out more about Thomas Bock - Sydney Morning Herald
4). William Evans served as Surgeon Superintendent on the convict ships Sir Willam Bensley in 1817, Bencoolen in 1819, Hindostan in 1821, Sir Godfrey Webster in 1826, Southworth in 1834 (VDL) and the Earl Grey in 1836
5). Hull Sessions - Trial of the last of the Dunhills - Sarah Stanhope, 30, was charged with stealing from William Schofield on 27th November, a bill case, containing a promissory note for 20, a bill value 15, three promissory notes of a guinea each, a pound note, and a sovereign. The jury returned a verdict of guilty and the Recorder proceeded to sentence her to be transported for 7 years. The above unhappy woman is the daughter of the notorious Snowden Dunhill, of whose family an account will be found below.
It is but rare in the history of crime to find cases parallel with the following condensing into one family an aggregate of guilt and such a weight of judicial infliction. The family to which we allude is that of the notorious Snowden Dunhill of Spaldington lane near Howden, and the daring and extensive depredations of whose gang justly rendered them the terror and invested their chief with a mysterious fame, such as might attach to the character of the Rob Roy, of the East Riding. This man was tried at York Assizes, 183 for robbing the granary of Mr. Clarkson at Holme, in the East Riding on 25th October preceding was found guilty and sentenced to 7 years transportation. There were 4 other bills preferred against him. Having gone through the term of punishment, he returned to this country and taking up his residence in Hull, he recommenced his old course and, about 3 years ago he was once more sentenced to transportation and is now if living at Botany Bay. In July last, George Dunhill aged 24 a handsome young man, son of the above was executed at Hobart Town,. DL. He was transported about 8 or 9 years ago along with his mother, and, at the same time, his sister Rosa was also convicted, and sentenced to 6 months imprisonment in York Castle. At last Leeds Borough Sessions she was found guilty of larceny and sentenced to 6 months imprisonment in Wakefield House of Correction where she now remains. Her two husbands William McDowell of Pontefract, and G. Conner of Leeds, were transported. Sarah (whose sentence of transportation is recorded above ) was imprisoned in York county Prison several years ago for 12 months and was again tried at Beverly last year. Her three husbands viz J. Stanhope, alias One armed Jem, W. Rhodes, and J. Crossland of Hull were each transported. William also a son of Snowden Dunhill was transported for 14 years, about 10 years ago, and died on his arrival at NSW. R. Taylor, a son of Mrs. Dunhill to a former husband, was also transported. Thus have we traced the dark events which have distinguished this ill-fated family, and here we must again remark that one so thoroughly criminal, whose guilt so uniformly extends alike through its matrimonial alliances and its hereditary descent is almost without parallel. Belfast Newsletter 29 January 1828 -
8) National Archives. Reference: ADM 101/4/7 Description: Medical and surgical journal of the Asia convict ship from 28 June 1823 to 18 January 1824 by William Evans, surgeon and superintendent during which time the said ship was conveying 150 male convicts from Woolwich to Hobart Town, Van Diemen's Land, New South Wales.