I've seen your posting history around various web sites and the advice to contact the RNLI, which I can only agree with.
I also note he served as skipper on a "3 masted ship".
As a skipper/master of a sea going vessel he would have to have had a certificate of competency; these and other records are held at the National Archives, Kew and there is also Lloyds Captain's Register. See http://www.nationalarchives.gov.uk/catalogue/RdLeaflet.asp?s...
for more details