Thomas Bor was born in Tramore, County Waterford, Ireland, on 12 February 1892, the eldest son of Edward Norman Cavendish Bor and Mabel Bor of Callan, County Kilkenney, Ireland. He was educated at Kilkenney College and joined the Merchant Marine at the age of fourteen and is reported to have served in China, Japan, South Africa, and New Zealand and in both sailing and steam ships including square riggers. Immediately Pre-WWI he served as the Chief Mate in the SS Uromi of the African Steam Ship Company and received his Captain’s Certificate in 1914 at the age of twenty-two.

He was appointed Probationary Sub Lieutenant, RNR, on 28 October 1914 and was posted to the Submarine Depot Ship HMS MAIDSTONE at Harwich ‘for Submarines’ to date 27 October 1914. His appointment to HMS E5 as Navigating Officer was dated 7 December 1914. He was promoted to Acting Lieutenant, RNR, to date 30 December 1914.

On 7 March 1916, HMS E5 was on patrol in the North Sea, North of Juist Island, when it was sighted by the German battle cruiser SMS Seydlitz. Some depth charges were dropped – apparently without effect. Later, a submarine, believed to be E5, was sighted by the German cruiser SMS Regensburg further East and close by a German minefield off the West of the Ems River. HMS E5 was not seen again and is thought to have been lost in the minefield. There were no survivors.

Thomas Bor is commemorated on the Portsmouth Naval War Memorial on Panel No. 22.