Two James Barrys born in 1852 Cork--same or different?

My great grandfather, James Barry, was born and died in Cork. His occupation was listed as telegraph clerk or telegraph assistant from 1881 on. His daughter (my grandmother) referred to him as a 'captain,' for which I could never find a reason. HIs father was Mathew Barry, a gardener. James' first wife was Anne McCarthy and his second wife was Mary Agnes Stack, with whom he had 11 children, starting in 1889. Addresses connected to him were Ballyhooly Road in 1881 (where his father lived) and Janemount in 1901 and 1911 Census. Yesterday I found a James Barry, born in Cork in 1852, who signed on with the British Navy and served from 1870 to 1885. Any ideas of how I can figure out if these are the same person or two different people? The ONLY reason I think it is possible is that seaman James was 'captain of the forecastle.' The reason against is that his father Mathew was still alive, but an aunt Catherine signed his volunteer papers when he was only 10 years old.