George David Maclaren was appointed to H.M.S. Magicienne, Captain Frederick T. Michell, in the Mediterranean 15 February 1840. H.M.S. Magicienne was build in 1812. 949 tons. 152 officers and men, 33 boys and 25 marines were employed on board. Ebenezer J. Brown was employed as Acting Assistant Surgeon. 
He was on the List of Surgeons of the Royal Navy fit for service in 1841.
George David MacLaren married Charlotte Elizabeth Ann MacLaren. They resided at Brockhurst Cottage, Gosport, Co. Southampton.
He was employed as Surgeon Superintendent on the William Hammond to Western Australia in 1856. He kept a Medical Journal from 6 December 1855 to 2 April 1856 -
During the period of this Journal the William Hammond has been employed in embarking male convicts in England and conveying them to Fremantle Western Australia. The embarkation took place during the winter season of the year at several of the parts along the Coast of England, yet, notwithstanding the very heavy gales and cold wet weather which prevailed in the channel the general health of the convicts and others did not suffer but continued remarkably good during the whole of the voyage, which was performed without touching at any intermediate part. 
George Maclaren was listed in the Medical Registry 1865 -
Staff Surgeon, Royal Navy.
Qualifications Lic. Royal College Surgeons, Edinburgh 1827 
Deputy Inspector-General of Hospitals and Fleets
He was promoted to the rank of Deputy Inspector-General of Hospitals and Fleets on the Retired List on 16 January 1866 
George David Maclaren, Deputy Inspector-General of Hospitals and Fleets died on August 3 at Brockhunt, Gosport.
He entered the Navy December 23, 1828 on board the Victory as Assistant Surgeon. He served on the East Indian station, and on the North American and West Indian Station; promoted to the rank of Surgeon December 28 1837. He was present at the bombardment and capture of St. Jean d'Acre, on November 3, 1840, for which he received the war medal for Syria and Turkish medal. Attained the rank of Staff surgeon in 1860; was raised to the rank of Deputy Inspector-General of Hospitals and Fleets on the retired List January 16 1866 and was granted Greenwich Hospital Pension March 28 1866.