There was a Richard Cannicott born c1841 who served in the Royal Marines Light Infantry. He married Hannah Trigger in 1863, giving his occupation as 'Marine in Her Majesty's Service'.
In 1861 he is onboard the ship Donegal moored at Hamoaze, but must have been serving (abroad?) in 1871 as Hannah an her children, including Richard born c1866, are at Battery Street, East Stonehouse, Devon.
In 1881 Richard Sr is in the Hospital Barracks at Walmer/Eastry, Kent & is a Lance Corporal RMLI. His wife is now Kate (Taylor), although the Banns in 1880 show him as a bachelor.
Hannah was very much alive, however, and in 1881 is in the Union Workhouse, Chard, along with Edith b1874 & Elizabeth c1877, but I'm not yet sure what happened to her after that.
The other children from 1871 are Emily (c1867) and George Edwin (1870), and in 1881 George is in the Budock Union Workhouse, Falmouth, along with another sibling, William, born 1873. Emily is an apprentice in Illminster, Chard, and Richard Jr is a Farm Servant in Falmouth.