Date of Seniority Royal Navy 31 December 1809
David Watson was entered in the Navy List of Medical Officers in 1814. 
He was employed as Surgeon Superintendent on two convict ship voyages to Australia:
He was was on the list of surgeons fit for service in 1841.
Notes and Links
1). Watson, At Yokohama, on the 24th August 1865, suddenly, David O. Watson, son of the late David Watson, surgeon, Royal Navy. - London and China Telegraph
28 October 1865
 Navy List