After the voyage of the Minverva in 1824 he was returning to England on the Royal Charlotte when, at Cato reef on 19th June she struck a reef and was wrecked. Leaving the survivors on shore, the chief officer and Dr. Nisbet with twelve others, got into the long boat and after 21 days made Moreton Bay where the Amity was immediately dispatched to assist those who had remained on board.
Dr. Nisbet sailed for Calcutta on the Norfolk in October 1825 and returned again as surgeon on Grenada in 1827 and then Hooghley in 1828.
The plaintiff (Dawson) who had gone out to Sydney as agent to the Australian Agricultural Company, was coming home to England by a return convict ship on board of which was also Mr. Nesbit a superintendent surgeon of convicts. One evening, at tea, the conversation between these two passengers turned upon the hot winds which prevail in those latitudes. Mr. Nesbit said they always blew with great violence. Mr. Dawon observed that the hot winds themselves were not violent, but were generally followed by squalls. The defendant declared he was satified they blew with violence, because he knew of boats having been upset by them. The plaintiff nevertheless maintained his opinion, and said he did not believe that such was the case, although.......The defendant, without suffering him to finish his sentence, struck him a blow on the nose, which drew blood, asking him at the same time how he presumed to contradict him? The plaintiff replied, that if he had not struck him, he was about to have added, "although I know you would not say so if you did not think it". The defendant then expressed his regret for the blow he had given him, and invited the plaintiff to shake hands; which invitation, however, he declined to accept, and left the ship on the first opportunity, to return home by one in which he would be relieved from the company of Mr. Nesbit. Verdict for the plaintiff. Damages £100..
He was on the List of Surgeons of the Royal Navy who were fit for service in 1841; he was appointed surgeon to the Cornwallis 
DEPUTY INSPECTOR HOSPITALS AND FLEETS
He was Deputy Medical Inspector of Hospitals and Fleets on half-pay in 1844 
In the 1851 Census Alexander Nisbet is recorded living at the Greenwich Hospital. He is employed as Deputy Inspector, unmarried and aged 56. His sister Jane Findlater also resided there. Also residing at Greenwich Hospital at this time was surgeon James McTernan and his wife and assistant surgeon Robert Beith
Alexander Nisbet married Lucy Susanna, daughter of Rev. E.J. Davenport of Davenport House, Shropshire at Arley Staffordshire in 1854.
PRESENTED TO THE QUEEN
In 1859 he was among the medical gentlemen presented to Her Majesty the Queen at St. James Palace 
In 1861 he lived at Her Majesty's Royal Naval hospital, Alverstoke with his wife Lucy and their children Alexander age 4 and Lucy age 3. Alexander aged 65 and Lucy 41. Jane Findlater, unmarried and age 42 still resided with him.
He received the good service pension in 1865 on the death of Sir J. Richardson
He is listed in the Medical Register 1865.
Residence Royal Hospital, Haslar, Gosport.
Qualifications Lic. Royal College Surgeons Edinburgh 1812.
M.D. University Edinburgh 1818.
KNIGHTED IN 1873
In June 1873 Alexander Nisbet R.N., and Captain George Biddlecombe, R.N. were introduced by the Earl of Kimberley, in the absence of the Secretary of State for the Home Department, and received the honour of Knighthood. 
Alexander Nisbet died at Arley Lodge, Lee, Kent on 22 June 1874. ...... Sir Alexander Nisbet M.D., late Inspector-General of Hospital in the Royal Navy and an Honorary Physician to the Queen, expired at Arley Lodge, at Lee, in Kent on the 22nd ult. 
His estate was valued at (under) £6000
MARRIAGE OF LUCY NISBET
On June 20 at Worfield Shropshire, the Rev. W. Kitching of Runnymeade, Old Windsore and of Tan-yr-Allt, Tremadoc, Carnarvonshire, to Lucy Susannah Nisbet, widow of Sir Alexander Nisbet, Inspector General, R.N., and daughter of the late Rev. E.S. Davenport of Davenport.