Thank you everyone for your help.
I think I've gone from knowing very little about Robert and his family to knowing quite a lot.
To summarise:
Robert Tubbs was born about 1772, based on his age at death. He may not have come from Norfolk at all but he was almost certainly from a coastal area (and probably from a seafaring family) and he became a seaman, probably at an early age.
1n 1799, aged about 27, he married Mary Chase in Great Yarmouth.
(Mary was born in Ormesby St Margaret in 1775, the daughter of Robert Chase and Jane Wacey)
By 1801 he had enlisted in the Royal Navy as a quarter gunner on HMS Hindoostan. His family were living in Caister next Yarmouth where 3 daughters were baptised, Mary and twins Jane and Elizabeth (who died soon after their birth.)
All the records except those of Caister name the family Tubbs, however,there were other families named Tubby in Caister so I imagine the parish clerk spelled Tubbs in the same way.
Robert moved ship in 1805 to HMS London then in 1809 to HMS Euralyus. Therafter he was discharged as "unserviceable" (?) and died in Stoke Damerel, Plymouth in 1819.
By 1812, Robert's wife, Mary Chase and their daughter Mary Tubbs had moved to Plymouth, where a son, Robert Tubbs, was baptised in 1812.
Mary Tubbs the daughter married another sailor, John Dale (spelled Deal in the Plymouth records) in 1819, the year her father died.
The following year, the widowed Mary Tubbs married a shipwright Thomas Holbrook, but died 3 years later in 1823.
