William Greenall Coe was born on 7 December 1891 at Notting Hill and the birth was registered at Kensington.  He was the younger child of William Churchyard Coe and his wife Elsie Adelaide (née Greenall).  William Coe (Sr) had been a postmaster and jobmaster (letting out horses and carriages for hire) in Notting Hill High Street, but had been bankrupted and subsequently worked as a jobmaster’s foreman in the City of London. William Coe (Jr) is recorded in the 1911 census as an engineer’s apprentice working for a motor omnibus builder.

He joined the Royal Navy as an Acting Engine Room Artificer 4th Class at Chatham on 4 May 1912, stating his date of birth as 7 December 1890, omitting his middle name, and giving his previous occupation as fitter and turner.  In September 1912 he joined the battleship HMS COMMONWEALTH, serving in the Mediterranean during the First Balkan War, and then moved to the minelayer HMS INTREPID in October 1913.

On 15 March 1915 he joined HMS DOLPHIN and the next month moved to HMS MAIDSTONE, the principal depot ship of the Eighth Submarine Flotilla based at Harwich, where he was advanced to ERA 3rd Class in May 1915.  HMS E1, together with E9, had been the first boats to enter the Baltic in October 1914, and were the start of a flotilla of eventually nine RN submarines operating from Reval (renamed Tallinn after 1918) in support of the Russian Baltic Fleet.  It is known that William Coe served in E1 but not clear when he joined.  However, he was drafted to DOLPHIN for three weeks in September 1915, and it is possible this enabled or preceded a passage to the Baltic.  From August 1916 the Baltic submarines came under the administrative control of HMS E19 (Cdr Francis Cromie).

William Coe died on 13 March 1917 in hospital in Reval (later Tallinn) from pneumonia and consumption.  He is buried at Tallinn Military Cemetery, Estonia.