I'm trying to fill in the gaps of my ggg-grandfather's time at sea. The earliest edition of the Navy List I've seen is for 1814. With the exception of the NA and Google books, the dates below were from a manuscript written by one of his sons:

The ORION 1802 - Surgeon's First Mate. (Will at National Archives dated 15Jan02)
The THUNDER from 20th January 1804 to 4th September 1805 - Surgeon.
The BARFLEUR from 7th March 1808 to 15th May 1809 - Surgeon.
The TRIUMPH in 1810 - Surgeon. (Google books)
The BARFLEUR from Oct. 1811 to Oct. 1812 - Surgeon.
The RAMILLIES from 9th October 1812 to 25th August 1815 - Surgeon.

Any pointers as to how to fill in the gaps and/or confirm start and end dates?

Regards

Stephen Plowman