James Lawrence was employed as Surgeon Superintendent on four convict ship voyages to Australia:
Ann and Amelia in 1825. The Ann and Amelia departed Cork on 8 September 1824 and arrived in Port Jackson on 2 January 1825.
John in 1832. The John departed the Downs 7th February 1832 and arrived in Port Jackson on 8th June 1832.
Lord Lyndoch in 1836. The Lord Lyndoch departed London 24 April 1836 and arrived in Van Diemen's Land on 20 August 1836.
Cressy in 1843. The Cressy departed Plymouth 30 April 1843 and arrived in Van Diemen's Land 20th August 1843.
Surgeon-Superintendent Emigrant Ship
He was appointed Surgeon to the emigrant ship Westminster in 1838. His Medical journal dated 28th March 1838 and 30th June 1838. He was paid £236/18/11d for his services on the Westminster .
James Lawrence was appointed to the Beaver in 1822 
In 1834 he was appointed surgeon to H.M.S Pique. The Ipswich Journal reported - this splendid ship, said to be the most beautiful frigate in the British navy, was built by the Surveyor of the Navy Captain Symonds at Plymouth Dock Yard. 190 tons of water could be stored in the iron tanks and six months provison under her hatches. The length of the upper deck was 171 feet, the main deck 164 feet 6 inches and the lower deck 160 feet. 
In February 1836 he was one of the Medical Witnesses at a controversial inquest into the death of a sailor who had been flogged at Woolwich. The Medical Witnesses were ridiculed in an article in the Lancet for their finding of Death by Visitation of God.