Many thanks, folks. He was at the same address in 1891 as a tobacconist, having dropped the "iron ship builder". In 1871 he was an iron ship builder and tobacconist in Stutton with Hazlewood near Tadcaster - which is nowhere near the sea! By 1901, when he was resident in the Charterhouse, he's down as a "retired iron plater in shipyard" which might be closer to the truth than iron ship builder.