Riwaka is a small town in the north of New Zealand's South Island. New Zealand is an Island country in the south-western Pacific Ocean comprising two main landmasses (the North Island and the South Island The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It lies beside Tasman Bay, five kilometres north of Motueka, and close to the mouth of the Riwaka River. Tasman Bay is a large V-shaped bay at the north end of New Zealand 's South Island. Motueka is a town in the South Island of New Zealand. It is located close to the mouth of the Motueka River, on the western shore of Tasman Bay The Riwaka River is located in the northwest of New Zealand 's South Island.