I had a quick look and found the following 1911 census James Martin as a boarder at 13 William Henry street Bootle occupation marine fireman. Place of birth Louth
1912 aboard the Empress of Britain same address as listed above estimated year of birth 1876 this may be out by a few years due to getting to sea early. Can't see any later sailings after 1912.
If the above is YOUR man he has a medal record for WW1 I will post the link below it will cost 3.50 to get a PDF to see if he actually claimed his medals as the Mercantile Marine medals had to be claimed they were not sent out, as a result quite a few went unclaimed if this is the case then NOK may claim them.http://discovery.nationalarchives.gov.u ... r/D8061866