In Maori legend the Araiteuru canoe (one of the large ancestral canoes that came from Hawaiki) was wrecked on Shag Point while on its way south in search of greenstone. Food-baskets and kumara on board were washed ashore. The kumara became irregularly shaped rocks and the circular food-baskets became the Moeraki Boulders, called by the Maori Te Kaihinake (the food-baskets). The reef at the mouth of the Shag River is said to be the petrified hull of the canoe, and a prominent rock nearby to be the mortal remains of its navigator, Hipo. Names of passengers are given to hills in the area. The legend is an example of how a colourful story would be woven around the physical features of the landscape to perpetuate a knowledge of geography in a culture without a written language.

Source http://www.dreamlike.info/nzl/otg/dc/moe/moeraki.htm