Thomas Fynes Clinton Dundas was born on 24 February 1859, and joined the Royal Navy as a Cadet aboard the Training Ship Britannia on 15 January 1872. He was promoted to Midshipman on 19 March 1874 and joined Topaze (June 1875) and Agincourt (July 1877). He was promoted to Acting Sub Lieutenant 19 September 1878 and confirmed in the rank with seniority 19 December 1878. Appointed ‘For Course’ to the Royal Naval college Greenwich in February 1880, and subsequently served aboard Carysfort (September 1880), Zephyr (October 1880), Cleopatra (August 1882) as Acting Lieutenant for Navigational Duties, and Champion (November 1882) as Acting Lieutenant for Navigational Duties. On promotion to Lieutenant on 29 June 1883 he served aboard Audacious (June 1883), Zephyr (August 1883), Champion(December 1883), Duke of Wellington(April 1884), Sultan (June 1884) and Condor (October 1884).

Whilst aboard Condor, he was landed for duty at Suakin 1884-85 during the naval and military operations in the Eastern Sudan. He served as Harbour Master at Suakin during the embarkation of the Indian Brigade and received Their Lordship’s approbation for the zeal and intelligence he displayed on supplying valuable information for the correction of the charts and sailing directions for the Red Sea. Captain Domvile praised his services as Harbour Master stating that he had brought several large steamers into harbour with safety. He next served aboard Jackal (November 1887) and Turquoise (June 1889). In the latter ship he served in the Naval Brigade landed under the Command of Vice Admiral Sir E. R. Fremantle, Commander-in-Chief East Indies Station, for the punitive Expedition against the Sultan of Witu in October 1890. He was mentioned in the Admiral's Despatch of 1 November 1890, published in the London Gazette of 6 January 1891: ‘The services of Lieutenant T. F. C. Dundas on the beach are specially deserving of mention’. Their Lordship's expressed their satisfaction in connection with the services he rendered to the French Gunboat Bomet, stranded at Zanzibar on 20 March 1890. He also received the thanks of the French Government for this service, on 6 January 1891.

He was next appointed to Asia (July 1891), and Amphion (December 1891) but was invalided from this ship in October 1893 suffering from liver disease and a weak heart, being admitted to Haslar Hospital for survey and found unfit for duty. He returned to duty aboard Victory (April 1894), and St. George (July 1894) but was invalided from that ship on 30 July 1895. He was found fit to resume service duties in January 1896 and was appointed to Bellerophon for Navigation Duties. He next joined Galatea (October 1896) but was Court Martialled on 26 February 1897 for negligently, or by default, hazarding the Galatea and was adjudged guilty and severely reprimanded. He served next aboard Ajax (March 1897), Iris (June 1897), and Collingwood (March 1898) ‘For duties with Gallway Division of the Coast Guard’. He finally joined Camperdown in October 1900, and retired at his own request on 9 March 1903 with the rank of Commander.