John Christiansen understated his age by 10 years to be allowed to enlist. He was aboard the Lady Nelson when she was torpedoed and then carried out temporary repairs so the ship could proceed to Mobile, Alabama for permanent repairs. For the most of the voyage he remained below deck in chest-high water to keep the Lady Nelson afloat and contracted malaria as a result.
Award Citation as published in London Gazette on 14 June 1945:
John Christianson [sic] is the Ship's Carpenter on a large merchant vessel which was torpedoed in the South Atlantic. Temporary repairs had to be effected at once and these were executed by Christianson. He displayed great courage and skill in helping to handle the disabled ship and assisting in bringing her to a United States port for repairs.