The main river systems, the Rewa, Navua, Sigatoka, and Ba, all have their headwaters in the central mountain area.
They are based in Navua, which is situated on the southern side of the main island of Viti Levu, between the town of Sigatoka and the city of Suva.
Sing started his teaching career at Savarekareka in Savusavu and went on to become the founding principal of Wairiki Secondary School in Taveuni, Bemana Junior Secondary School in Sigatoka, Lomary Secondary School, and the first lay principal of St Johns College in Cawaci.