This is what I have on the family so far:
John was a mariner, fisherman.
1871 Census Jurby District, Rushen IOM lists E.Jane Cubbon age 28 fisherman's wife and daughter
Louisa Jan Cubbon age one.
1871 Census - list John on the Linnet CT 31 fishing boats.
1881 Census Rushen Isle of Man - lists Isabella - fisherman's wife
children Lousia, Emily, John & Thomas all born Rushen, IOM
1881 Census - John as 37 years, working on the Honey Bee - Fishing at Kinsale Mackerel Fishing.
1891 Census lists just Isabella Cubbon age 45 born Rushen IOM on Ballafesson Road, Rushen
1891 Census lists John Cubbon age 47 on the Confidence Boat CI 25 - town St Mary.
1901 Census lists John (Mariner) and Emma Cubbon ages 57 and 48, Emma is born in Lancashire, England. They are living on Station Road, Port Erin, Rushen IOM.