In about 1868 he attended Takamoa Theological College, Rarotonga, then under James Chalmers.
He was one of six Polynesians chosen to convert New Guinea, and with his wife, Tungane, landed at Manumanu on the coast of Papua in November 1872.
Five months later Ruatoka and three colleagues sailed for Port Moresby, where he remained until his death.
As well as being a successful evangelist, he served as a guide, interpreter and advisor to the English missionaries.
Ruatoka and his wife taught the locals of Papua New Guinea, Cook Islands dancing and songs; more than 100 years later "Aito Pakapaka" was sung by Moses Tau and Te Marama which is sung by the People of Ruatoka.