History of the Bahá'í Faith in Tanzania says that Claire Gung was the 1st pioneer of the Bahá'í Faith in the country. Her biography, Claire Gung: Mother of Africa p14 confirms that she disembarked the The Warwick Castle sometime in February, 1951.

Claire Gung arrived in Tanganyika aboard the Warwick Castle and obtained employment as a matron in a boys' boarding school in Lushoto. She was the second Bahá'í pioneer to the country. [CG160; CBN No 18 Mar 1951 p10]
• She later pioneered to Uganda and Southern Rhodesia during the Ten Year Crusade.
• An additional group of early arrivals in East Africa settled in Tanganyika in 1951. They included Hassan and Isobel Sabri who came from Egypt, and Jalal Nakhjavání and his family from Iran. By 1954, a Local Spiritual Assembly had been elected in Dar es Salaam including three native believers. Among them was Denis Dudley-Smith Kutendele, the first to accept the Faith in Tanzania. [A Brief Account of the Bahá'í Faith in Africa Since 1953 by Nance Ororo-Robarts and Selam Ahderrom p2]
  History of the Bahá'í Faith in Tanzania said that the first local spiritual assembly was elected in Dar es Salaam in 1952 and that it received civic registration later under Tanganyika's Trustee's Incorporation Ordinance.