Frederick Hubbard was born early in 1886 and baptised on 21 February at Cheam, Surrey, the fifth of eight children of Elijah Hubbard, a farm labourer, and his wife Mary Ann (née Gatton).  Elijah died in 1893 and Mary Ann died in 1900, and the family were dispersed. In the 1901 census, Frederick was recorded as a 15 year old lodger with another family in Cheam, working as a Telegraph Messenger, while his younger brothers were inmates in the workhouse.

He joined the Royal Navy as a Stoker 2nd Class at Portsmouth on 9 October 1906, stating his date of birth as 6 December 1887 and his previous occupation as milk carrier. After initial training he served in the reserve scout frigate HMS FORESIGHT and then the armoured cruiser HMS ANTRIM. In the early part of 1910 he served in the refitting battleship HMS RENOWN, before being sent in May 1910 to HMS EGMONT, the Malta depot ship.

He returned to Portsmouth in June 1912 and joined the submarine depot ship HMS DOLPHIN on 23 October. A year later on 23 October 1913, he was drafted to HMS MAIDSTONE for E5.  From August to October 1914 he was sick with an injury to his left forearm. On 5 October 1914 he re-joined MAIDSTONE, now as an Acting Leading Stoker, and possibly at this point transferred to HMS E7.  At the end of May 1915, E7 sailed from Harwich in company with E2 and E12 for the Mediterranean, subsequently coming under the depot ship HMS ADAMANT in June 1915.

HMS E7 completed one highly successful patrol in the Sea of Marmara during June/July 1915 for which her CO, Lt Cdr Archibald Cochrane, was awarded the DSO, and several crew members earned DSMs. Whilst attempting to re-enter the Dardanelles on her next patrol, E7 became entangled in newly-laid anti-submarine nets off Nagara Point. On 4 September 1915, after many hours attempting to work free, Turkish/German attacks forced her to the surface where her crew were all taken prisoner and E7 was scuttled to avoid capture. 

Leading Stoker Hubbard died from illness on 11 November 1916 at Angora (Ankara), Turkey, one of four members of the crew of E7 to die in captivity. His original grave was not located, but he is commemorated at the Baghdad (North Gate) War Cemetery, Iraq.

His death was notified to his eldest sister, Mrs Beatrice Mills (née Hubbard).  One of his younger brothers, Stratton Hubbard, also served as a Leading Stoker in HM Submarines between 1915 and 1921, serving in HMS B1, V2 and G4.