Tasman joined the unit on Timor as a Private from 2/40 Battalion, after the fall of Koepang, approx March 1942. He was one of the former Koepang men, who moved to the village of Mape for intensive commando training and joined No 4 Section, “B” Platoon.
After the campaign on Timor, he embarked with the unit, for Australia aboard the Royal Dutch destroyer “Tjerk Hiddes” on either 11 Dec 1942 or 16 Dec 1942, as the embarkation rolls do not differentiate.
On return to Australia he joined 2/12th Battalion, serving in New Guinea and Borneo. He was discharged on 18 Dec 1945.