As he was a fisherman, sailor then unless the boat was in Port on census night he will not show on any census records.

Very likely he died at sea, this guide should help for information where to find records. You could also try searching Newspapers online on Findmypast or British Library Newspaper Archive to see if his death was reported in any.

http://www.nationalarchives.gov.uk/help-with-your-research/research-guides/birth-marriage-death-sea-or-abroad/