Hi Ruskie,
Thanks again for your time. I have the family in 1851 as:
1851 census, Pountney, St Laurence London City
SILVERTON George Head 45 Born Gillingham Boatman
SILVERTON Jane Wife 41 Gillingham
SILVERTON Jane Dau 19 Gillingham
SILVERTON Edward Son 16 Gillingham
SILVERTON Betsy Dau 9 Gillingham
SILVERTON John Son 5 Gillingham
In 1861 his occupation is RIVER Contractor.
Paul Ward