Lewis, a son of Murdo and Elizabeth nee O'Keefe, was born on board the 'Sir Lancelot' and, like his father before him, he made his living from sailing. He served in the Clan Line and became a Master Mariner after which he joined the Bengal Pilot Service on the Hooghly River. By the time he reached retirement (1946) he was Port Captain at Calcutta

Lewis was married to Janet Cameron from Glasgow with issue; Catriona Margaret Macdonald (b 1921) who married an Australian named Grant; with issue, and Ailsa Cameron Macdonald (b1928) who married Thomas Mylechreest; with issue