William served as a Master in the Royal Navy.
On June 12, 1845 he married Mary Emma Pope (born Sparrow), a widow. One of the witnesses at the marriage was “S. H. Petherbridge”, likely his niece Susan Hyne Petherbridge, eldest daughter of his late sister Louisa.
In 1846 he had a son, William Charles Sparrow Hyne.
In 2018, two Royal Navy medals belonging to William were auctionned. The auction notes include the following information about his navy career:
William Ellis Hyne served as a Volunteer in Albion at Navarino. He commanded the boats of Conflict at the capture of the piratical slaver Nympha in 1830, on which occasion he was wounded. Acting Master of Nimrod in the operations on the coast of China, 1840-42, and on the coast of Scinde in 1843. He was commissioned Master, for 5th Rate vessels, on 14 December 1843, and died at Penzance in 1850.
In 1848, William was assigned to command the Coast Guard station at Mouse Hole in Cornwall, England.
William died August 7, 1850 in the district of Penzance, in the county of Cornwall.